Patent Publication Number: US-11665824-B2

Title: Power converter module

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Continuation Application of U.S. patent application Ser. No. 17/147,219 filed on Jan. 12, 2021 and entitled “POWER CONVERTER MODULE”, which claims priorities to China Patent Application No. 202011164463.3, filed on Oct. 27, 2020 and China Patent Application No. 202011239669.8, filed on Nov. 9, 2020. The entireties of the above-mentioned patent applications are incorporated herein by reference for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to a power converter module, and more particularly to a power converter module with a plurality of positive copper layers and a plurality of negative copper layers staggered. 
     BACKGROUND OF THE INVENTION 
     With the rapid development of technologies such as mobile communications and cloud computing, high-power power converter modules have been widely used in electronic products. Due to the trend of high power and miniaturization of electronic products, how to improve the conversion efficiency of the power converter module and reduce the size of the power converter module is the primary consideration. 
     As the output power of the existing power converter module increases, the large current in the power converter module causes more and more losses in the corresponding current loop and flow path, and the proportion of this loss in the total loss of the power converter module also increases. In order to reduce the loss on the transmission path, multiple copper layer wirings in the multilayer printed circuit board are often connected in parallel to reduce the equivalent impedance of the flow path. However, due to the existence of parasitic parameters between multiple copper layers and the AC loop in the power converter module. This increases the AC loss of the AC current in the corresponding AC circuit, thereby reducing the conversion efficiency of the power conversion module. 
     Therefore, there is a need of providing a power converter module to obviate the drawbacks encountered from the prior arts. 
     SUMMARY OF THE INVENTION 
     It is an object of the present disclosure to provide an apparatus. By staggering a plurality of positive copper layers and a plurality of negative copper layers, and the positive copper layers and the plurality of negative copper layers are electrically connected to the corresponding switching positive and negative terminals, the capacitor positive and negative terminals, and a plurality of vias respectively. The projections of the adjacent positive and negative copper layers and capacitor area on the first surface partially overlap with each other, thereby reducing the parasitic inductance of the wiring and reducing the parasitic loss. Therefore, the conversion efficiency of the power conversion apparatus is improved. 
     In accordance with an aspect of the present disclosure, there is provided an apparatus. The apparatus includes a substrate, at least one switching device, at least one capacitor device, at least one first via, at least one second via, at least one third via and at least one fourth via. The substrate has a first surface and a second surface, the first surface and the second surface are opposite, the substrate includes a plurality of copper layers, the plurality of copper layers includes M positive copper layers and N negative copper layers, and the M positive copper layers and the N negative copper layers are alternated, wherein M is equal to or greater than one, N is equal to or greater than one, and the sum of M and N is equal to or greater than three. The switching device is disposed on the first surface of the substrate and includes a switching positive terminal and a switching negative terminal. The capacitor device is disposed on the first surface of the substrate and includes a capacitor positive terminal and a capacitor negative terminal, and the at least one capacitor device forms a capacitor area. The first via is electrically connected to the switching positive terminal, the second via is electrically connected to the switching negative terminal, the third via is electrically connected to the capacitor positive terminal, and the fourth via is electrically connected to the capacitor negative terminal. The positive copper layers are electrically connected to the first via and the third via, and the negative copper layers are electrically connected to the second via and the fourth via. A dielectric layer is disposed between the two adjacent copper layers. The projections of the adjacent positive and negative copper layers and capacitor area on the first surface at least partially overlap with each other. 
     In accordance with an aspect of the present disclosure, there is provided a manufacturing method of an apparatus. The manufacturing method of an apparatus comprises steps: providing a substrate having a first surface and a second surface opposite to each other, wherein the substrate comprises a plurality of copper layers, the plurality of copper layers comprises M positive copper layers and N negative copper layers, and the positive copper layers and the negative copper layers are alternated, wherein M is equal to or greater than one, N is equal to or greater than one, and the sum of M and N is equal to or greater than three; providing at least one switching device disposed on the first surface of the substrate, wherein the switching device comprises a switching positive terminal and a switching negative terminal; providing at least one capacitor assembly disposed on the first surface of the substrate, wherein the capacitor assembly comprises a capacitor positive terminal and a capacitor negative terminal, and the at least one capacitor assembly forms a capacitor area; providing at least one first via, at least one second via, at least one third via and at least one fourth via, wherein the first via is electrically connected to the switching positive terminal, the second via is electrically connected to the switching negative terminal, the third via is electrically connected to the capacitor positive terminal, and the fourth via is electrically connected to the capacitor negative terminal, wherein the positive copper layers are electrically connected to the first via and the third via, and the negative copper layers are electrically connected to the second via and the fourth via; wherein projections of the adjacent positive and negative copper layers and the capacitor area on the first surface at least partially overlap with each other. 
     The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic perspective view illustrating a power converter module according to an embodiment of the present disclosure; 
         FIG.  2    is an exploded view illustrating the power converter module according to the embodiment of the present disclosure; 
         FIG.  3    is a schematic side view illustrating the power converter module according to the embodiment of the present disclosure; 
         FIG.  4    is a schematic side view illustrating the power converter module according to the embodiment of the present disclosure; 
         FIG.  5    is a schematic view illustrating the second surface of the power converter module according to the embodiment of the present disclosure; 
         FIG.  6    is a schematic equivalent circuit diagram illustrating the power converter module of the present disclosure; and 
         FIG.  7    is a schematic side view illustrating the power converter module according to another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this disclosure are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed. 
       FIG.  1    is a schematic perspective view illustrating a power converter module according to an embodiment of the present disclosure.  FIG.  2    is an exploded view illustrating the power converter module according to the embodiment of the present disclosure.  FIG.  3    is a schematic side view illustrating the power converter module according to the embodiment of the present disclosure.  FIG.  4    is a schematic side view illustrating the power converter module according to the embodiment of the present disclosure. As shown in  FIGS.  1 ,  2 ,  3 , and  4   , the power converter module  1  includes a multilayer printed circuit board  10 , at least one switching device  101 , at least one capacitor device  102 , at least one magnetic core element  103  and at least one winding via  105 . The multilayer printed circuit board  10  has a first surface  11 , a second surface  12  and an inside layer  14 . The first surface  11  and the second surface  12  are opposite, and the multilayer printed circuit board  10  includes a plurality of copper layers L1 to L8. The switching device  101  is disposed on the first surface  11  of the multilayer printed circuit board  10 . The magnetic core element  103  is disposed in the inside layer  14  of the multilayer printed circuit board  10 , and the magnetic core element  103  has at least one hole  104 . A first end of the winding via  105  is electrically connected to the switching device  101 , and a second end of the winding via  105  is electrically connected to the second surface  12  of the multilayer printed circuit board  10 . The winding via  105  penetrates through the hole  104  of the magnetic core element  103  and forms a magnetic assembly with the magnetic core element  103 . The winding via  105  is electrically connected to all or a part of the copper layers L1 to L8. The capacitor device  102  is disposed on the first surface  11  of the multilayer printed circuit board  10 . The capacitor device  102  includes at least one capacitor, and the capacitor is an input capacitor or an output capacitor. In an embodiment, the winding via  105  is a straight hole or a stepped hole, more specifically, the winding via  105  may have a straight structure or a partially bent structure. The amount of the copper layers on a first side of the magnetic core element  103  close to the first surface  11  of the multilayer printed circuit board  10  is at least two more than the amount of the copper layers on a second side of the magnetic core element  103 . In an embodiment, the amount of the copper layers on the first side of the magnetic core element  103  close to the first surface  11  of the multilayer printed circuit board  10  is at least three more than the amount of the copper layers on the second side of the magnetic core element  103 . As shown in  FIGS.  3  and  4   , the multilayer printed circuit board  10  includes eight copper layers L1 to L8 and eight dielectric layers PP. The dielectric layer PP is disposed between the two adjacent copper layers, however, the actual amount of the layers of the multilayer printed circuit board  10  is not limited thereto. In an embodiment, the magnetic core element  103  is disposed between the copper layers L7 and L8 of the multilayer printed circuit board  10 . As a result, the amount of the copper layers L1 to L7 on the first side of the magnetic core element  103  close to the first surface  11  of the multilayer printed circuit board  10  is more than the amount of the copper layer L8 on the other second side of the magnetic core element  103 , and the copper layers L1 to L7 can have a larger wiring area and a larger copper laying area. Since the amount of the copper layers on one side of the magnetic core element  103  is more than the amount of the copper layers on the other side of the magnetic core element  103  (e.g., by two), a larger amount of copper layers concentrated on one side of the magnetic core element  103  can be used to obtain a larger wiring area and a larger copper laying area. Accordingly, enough space for wiring is provided to avoid the strong electromagnetic field interference caused by the power loop. Moreover, the flexibility of the copper laying network is increased, and the parasitic resistance and parasitic inductance of the multilayer printed circuit board are reduced, thereby improving the efficiency of power converter module. 
       FIG.  5    is a schematic view illustrating the second surface of the power converter module according to the embodiment of the present disclosure. In an embodiment, as shown in  FIG.  5   , the power converter module  1  further includes at least one pad  13 , and the at least one pad  13  is disposed on the second surface  12  of the multilayer printed circuit board  10 . The pad  13  is a copper block pin or the surface copper skin of the multilayer printed circuit board  10 . The pad  13  is fixed on the second surface  12 , and the second end of the winding via  105  is electrically connected to the pad  13 . 
       FIG.  6    is a schematic equivalent circuit diagram illustrating the power converter module of the present disclosure. As shown in  FIG.  6   , the capacitor device  102  includes an input capacitor Cin and an output capacitor Co, the magnetic assembly is an inductor Lo, and the winding via  105  is served as the winding of the inductor Lo. The switching device  101  includes at least one upper switch  1010  and at least one lower switch  1011  electrically connected to each other. The upper switch  1010  and the lower switch  1011  can be, for example, MOSFET (Metal Oxide Semiconductor Field Effect Transistor), but not limited thereto. A node SW is formed between the upper switch  1010  and the lower switch  1011 , the node SW is electrically connected to the inductor Lo, and the node SW is electrically connected to the first end of the winding via  105 . An end of the input capacitor Cin is electrically connected to the upper switch  1010  to form a positive input Vin+, the other end of the input capacitor Cin is electrically connected to the lower switch  1011  to form a negative input Vin−. Two ends of the output capacitor Co are connected to the inductor Lo and lower switch  1011 , respectively. In an embodiment, the inductor Lo is regarded as the magnetic assembly of the above embodiment and is disposed in the inside layer  14  of the multilayer printed circuit board  10 . The projections of the inductor Lo and the switching device  101  on the first surface  11  at least partially overlap with each other. The inductor Lo is electrically connected to the positive output Vo+ of the power converter module  1 , and the positive output Vo+ is disposed on the second surface  12  of the multilayer printed circuit board  10 . It is noted that only single-phase half-bridge branch is shown in  FIG.  6   , however, the actual power converter module may include multiple-phase half-bridge branches connected in parallel. 
       FIG.  7    is a schematic side view illustrating the power converter module according to another embodiment of the present disclosure. The elements of  FIG.  7    that are similar with those of  FIG.  4    are represented by the same reference numerals, and the detailed description thereof is omitted herein. In the embodiment shown in  FIG.  7   , the plurality of copper layers include a plurality of positive copper layers and a plurality of negative copper layers, and the plurality of positive copper layers and the plurality of negative copper layers are disposed in staggered arrangement. In an embodiment, the positive copper layers include copper layers L3, L5, and L7, and the negative copper layers include copper layers L2, L4, and L6. The switching device  101  has a switching positive terminal  101   a  and a switching negative terminal  101   b . The capacitor device  102  has a capacitor positive terminal  102   a  and a capacitor negative terminal  102   b . The capacitor device  102  is disposed on the first surface  11  and is adjacent to the switching device  101 , and the capacitor device  102  forms a capacitor area. The power converter module  1  further includes a first via  106 , a second via  107 , a third via  108  and a fourth via  109 . The first via  106  is electrically connected to the switching positive terminal  101   a , the second via  107  is electrically connected to the switching negative terminal  101   b , the third via  108  is electrically connected to the capacitor positive terminal  102   a , and the fourth via  109  is electrically connected to the capacitor negative terminal  102   b . The first via  106  and the third via  108  are electrically connected to a part of the copper layer L1 (i.e., the part of the copper layer L1 that is electrically connected to the switching positive terminal  101   a  and the capacitor positive terminal  102   a ), the copper layers L3, L5, L7, and a part of the copper layer L8 (i.e., the part of the copper layer L8 that is electrically connected to the positive input Vin+). The second via  107  and the fourth via  109  are electrically connected to a part of the copper layer L1 (i.e., the part of the copper layer L1 that is electrically connected to the switching negative terminal  101   b  and the capacitor negative terminal  102   b ), the copper layers L2, L4, L6, and a part of the copper layer L8 (i.e., the part of the copper layer L8 that is electrically connected to the negative input Vin−). The positive copper layers and the negative copper layers are disposed in staggered arrangement. The first via  106  and the third via  108  are electrically connected to the positive input Vin+, and the second via  107  and the fourth via  109  are electrically connected to the negative input Vin−. The positive input Vin+ and the negative input Vin− are disposed on the second surface  12  of the multilayer printed circuit board  10 . The arrow line in  FIG.  7    represents the direction of the AC current of this embodiment. The AC current loop of this embodiment is exemplified as follows. Taking the capacitor positive terminal  102   a  of the capacitor device  102  as a starting point, the AC current flows through the third via  108  and each positive copper layer, and then flows into the switching positive terminal  101   a  of the switching device  101  through the first via  106 . Taking the switching negative terminal  101   b  of the switching device  101  as a starting point, the AC current flows through the second via  107  and each negative copper layer, and then flows into the capacitor negative terminal  102   b  of the capacitor device  102  through the fourth via  109 . The direction of the AC current flowing through the positive copper layer is opposite to the direction of the AC current flowing through the adjacent negative copper layer. The overlapping parts of the first and third vias  106  and  108  and the copper layer L2, L4, and L6 shown in  FIG.  7    only represent the front-to-rear relationship between the via and the copper layer under this viewing angle condition, rather than the actual connection. Similarly, the overlapping parts of the second and fourth vias  107  and  109  and the copper layers L3, L5, and L7 only represent the front-to-rear relationship between the via and the copper layer under this viewing angle condition, rather than the actual connection. The AC current flowing through the adjacent copper layers are in opposite directions so that the AC magnetic fluxes between the adjacent copper layers cancel each other out, thereby reducing the parasitic inductance of the current loop. Consequently, the conversion efficiency of the power conversion module is improved. 
     In addition, the power converter module  1  further includes a dielectric layer PP, and the dielectric layer PP is disposed between two adjacent copper layers. The projections of the adjacent positive and negative copper layers and the capacitor area on the first surface  11  at least partially overlap with each other, thereby reducing the parasitic inductance of wiring and reducing the parasitic loss. Therefore, the conversion efficiency of the power converter module  1  is improved. In an embodiment, the first via  106 , the second via  107 , the third via  108 , and the fourth via  109  are straight holes or stepped holes. 
     In an embodiment, a part of the copper layer L8 is electrically connected to the positive output of the power converter  1 , and a part of the copper layer L8 is electrically connected to the negative output of the power converter module  1 . 
     In an embodiment, when the amount of the positive copper layer on the side of the magnetic core element  103  is one, and the amount of the negative copper layer is also one, the amount of the copper layers on one side of the magnetic core element  103  is two more than the amount of the copper layers on the other side of the magnetic core element  103 . 
     It should be noted that the side view shown in  FIG.  4    focuses on showing the position and connection relationships of the copper layers, the magnetic core element and the corresponding winding via. The side view shown in  FIG.  7    focuses on showing the electrical connections of the positive and negative copper layers, the switching device and the capacitor device. In fact, the structures shown in  FIGS.  4  and  7    can be implemented in different power converter modules or in the same power converter module. 
     From the above descriptions, the present application provides a power converter module. The amount of the copper layers on one side of the magnetic core element is more than the amount of the copper layers on the other side of the magnetic core element. Therefore, a larger amount of copper layers concentrated on one side of the magnetic core element can be used to obtain a larger wiring area and a larger copper laying area. Accordingly, enough space for wiring is provided to avoid the strong electromagnetic field interference caused by the power loop. Moreover, the flexibility of the copper laying network is increased, and the parasitic resistance and parasitic inductance of the multilayer printed circuit board are reduced, thereby improving the efficiency of power converter module. The present application provides a power converter module, by staggering the plurality of positive copper layers and the plurality of negative copper layers, and the plurality of positive copper layers and the plurality of negative copper layers are electrically connected to the corresponding switching positive and negative terminals, the capacitor positive and negative terminals, and a plurality of vias respectively. The projections of the adjacent positive and negative copper layers and the capacitor area on the first surface at least partially overlap with each other, thereby reducing the parasitic inductance of the wiring and reducing the parasitic loss. Therefore, the conversion efficiency of the power conversion module is improved. 
     While the disclosure has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.