Abstract:
Identical planar electronic components are stacked in an assembly. Each component has two contact metallizations positioned on edges of a same surface of the component. The components are stacked along a common axis. Each successive component is rotated about the common axis by a fixed angle. A value of the fixed angle is selected to position, side by side, the contact metallization of one component and the contact metallization of another next component adjacent to each other in the stack. Electrical connections are provided between two adjacent contact metallizations.

Description:
PRIORITY CLAIM 
       [0001]    This application claims the priority benefit of French Application for Patent No. 1656944, filed on Jul. 21, 2016, the disclosure of which is hereby incorporated by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to an assembly of electronic components and more particularly to a vertical stack of electronic components. 
       BACKGROUND 
       [0003]      FIGS. 1A and 1B  illustrate a planar square-shaped electronic component  1 . Electronic component  1  may, for example, be a microbattery. 
         [0004]      FIG. 1A  is a top view. Component  1  comprises two contact metallizations  3  and  5 , for example, the positive + and negative − terminals of a microbattery. Metallizations  3  and  5  are positioned on the edge of component  1 , for example, on two consecutive corners of an upper surface  7  of component  1 . Contact metallizations  3  and  5  are, for example, triangular and have a top corresponding to the corner of component  1 . 
         [0005]      FIG. 1B  is a side view of electronic component  1 . Contact metallization  5  is positioned in a corner of upper surface  7  of component  1  and does not extend through the component. The same applies to contact metallization  3 , not shown in  FIG. 1B . 
         [0006]      FIG. 2  illustrates a parallel assembly of electronic components  1  of the type shown in  FIGS. 1A and 1B . The components are stacked along an axis Z orthogonal to the plane of the components, and are shifted with respect to one another by a length L, along an axis X orthogonal to axis Z and to the side of the component supporting metallizations  3  and  5 . Length L is selected to expose contact metallizations  3  and  5  of each successive component  1 . Contact metallizations  3  and  5  of components  1  are respectively interconnected by connections  11  and  13 , for example, weld lines. 
         [0007]    The assembly of  FIG. 2  has the disadvantage of being bulky and unreliable when a large number of components  1  need to be stacked. 
       SUMMARY 
       [0008]    An embodiment aims at forming an assembly of electronic components which avoids at least some of the disadvantages of existing assemblies. 
         [0009]    An embodiment provides an assembly of electronic components enabling to stack a large number of electronic components with a low bulk. 
         [0010]    An embodiment provides an assembly of electronic components enabling to connect the electronic components in parallel and/or in series. 
         [0011]    Thus, an embodiment provides an assembly of identical planar electronic components having two contact metallizations positioned on edges of a same surface of each component, the components being stacked along an axis Z orthogonal to their plane, wherein each successive component is rotated around axis Z by a fixed angle, the fixed angle being selected to position side by side one of the contact metallizations of a component and one of the contact metallizations of the next component, the assembly further comprising connections between two adjacent contact metallizations. 
         [0012]    According to an embodiment, the two contact metallizations form a positive terminal and a negative terminal of a microbattery. 
         [0013]    According to an embodiment, the electronic components are series-connected by selecting the fixed angle to position side by side the positive terminal of a microbattery and the negative terminal of the next microbattery. 
         [0014]    According to an embodiment, the electronic components are connected in parallel by selecting the fixed angle to position side by side the positive terminal of a microbattery and the positive terminal of the next microbattery. 
         [0015]    According to an embodiment, the electronic components have a square or rectangular shape. 
         [0016]    According to an embodiment, each contact metallization is positioned on one of the corners of the component. 
         [0017]    According to an embodiment, the electronic components have a circular shape. 
         [0018]    According to an embodiment, each contact metallization is formed on an extension extending inside of the component periphery. 
         [0019]    According to an embodiment, each contact metallization is positioned on the edge of the component and associated with an opening intended to connect said contact metallization with a contact metallization of another component. 
         [0020]    According to an embodiment, the connections are joined by a weld or solder. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The foregoing and other features and advantages will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings, wherein: 
           [0022]      FIGS. 1A and 1B , previously described, are respective top and side views of a planar electronic component; 
           [0023]      FIG. 2 , previously described, is a top view of an example of assembly of electronic components of the type in  FIGS. 1A and 1B ; 
           [0024]      FIG. 3A  is a top view of an embodiment of a parallel assembly of electronic components of the type in  FIGS. 1A and 1B ; 
           [0025]      FIG. 3B  is a top view of an embodiment of a series assembly of electronic components of the type in  FIGS. 1A and 1B ; 
           [0026]      FIG. 4A  is a top view of an alternative embodiment of the electronic component of the type in  FIGS. 1A and 1B ; 
           [0027]      FIG. 4B  is a top view of an embodiment of an assembly of electronic components of the type in  FIG. 4A ; 
           [0028]      FIG. 5A  is a top view of another alternative embodiment of the electronic component of the type in  FIGS. 1A and 1B ; and 
           [0029]      FIG. 5B  is a top view of an embodiment of an assembly of electronic components of the type in  FIG. 5A . 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    The same elements have been designated with the same reference numerals in the different drawings. For clarity, only those steps and elements which are useful to the understanding of the described embodiments have been shown and are detailed. 
         [0031]    In the following description, when reference is made to terms qualifying a relative position, such as terms “top” and “upper”, or to terms qualifying the orientation, such as term “vertical”, reference is made to the orientation of the element considered in the drawings. Unless otherwise specified, expression “in the order of” means to within 10%, preferably to within 5%. 
         [0032]      FIG. 3A  is a top view of an embodiment of a parallel assembly of electronic components  1  of the type shown in relation with  FIGS. 1A and 1B . Components  1  are stacked along a common axis Z, orthogonal to the plane of components  1 . Axis Z is arranged at the center of the components. Each component has been submitted to a rotation about the common central axis Z by a fixed angle “a” with respect to the previous component. Contact metallizations  3  of the successive components are thus spaced apart and adjacent. Contact metallizations  3  of the successive components may be connected by a weld or solder electrical connection  15 . Similarly, contact metallizations  5  of the successive components may be connected by a weld or solder  15 . In this example, fixed angle “a” is in the order of 10 degrees. As shown in  FIG. 3A , weld or solder electrical connection  15  connects two successive contact metallizations  3  and  5  but, as a variation, the weld or solder connection  15  might extend all along contact metallizations  3  or  5  to connect a plurality thereof at a time. This assembly enables to stack a large number of components while being stable and compact. Indeed, whatever the number of stacked components, the largest lateral dimension of the stack does not exceed the length of the side of component  1  multiplied by the square root of two. 
         [0033]      FIG. 3B  is a top view of an embodiment of a series assembly of electronic components  1 . The series assembly of electronic components  1  shown herein is similar to the parallel assembly shown in  FIG. 3A , with the difference that components  1  are series-connected. To achieve this, the contact metallization  3  of a component is adjacent to the contact metallization  5  of the previous component. The components are then shifted by a 90-degree angle and then by a fixed angle “a” in the order of 10 degrees. However, in this case, only two contact metallizations  3  and  5  of successive components are adjacent and a weld or solder electrical connection  15  can only contact two adjacent contact metallizations at a time. In the illustrated example, terminal  3 A of the first stacked component forms a first terminal of the series assembly and terminal  5 B of the last stacked component forms the second terminal of the series assembly. 
         [0034]    As a variation, contact metallizations  3  and  5  might be positioned on diagonal corners of a component. In this case, the parallel assembly would remain unchanged. To form a series assembly, it would be sufficient to submit each component  1  to a rotation of axis Z by a 180-degree angle followed by a rotation of axis Z by a fixed angle “a” in the order of 10 degrees. 
         [0035]      FIG. 4A  is a top view of a variation  20  of the embodiment of electronic component  1  of  FIGS. 1A and 1B  adapted to the assemblies described in relation with  FIGS. 3A and 3B . Electronic component  20  is a planar electronic component of circular shape comprising two diametrically opposite extensions  22  and  24  protruding from the periphery of component  20 . The two contact metallizations  3  and  5  do not extend through the component and respectively rest on the component edge and more particularly on extensions  22  and  24 . As an example, extensions  22  and  24  are oval-shaped. 
         [0036]      FIG. 4B  is a top view of an embodiment of a parallel assembly of electronic components  20  of  FIG. 4A . The assembly designated herein has the same characteristics as the assembly shown in relation with  FIG. 3A . Components  20  are stacked along a common axis Z and have been submitted to a rotation about the common central axis Z by a fixed angle “a” with respect to one another. In this example, fixed angle “a” is in the order of 8 degrees. In the same way as in  FIG. 3A , adjacent contact metallizations  3 ,  5  of the successive components  20  are connected one by one by a weld or solder electrical connection  15  but, as a variation, the weld or solder electrical connection  15  may connect a plurality of contact metallizations at a time. 
         [0037]    It is possible to form a series assembly of electronic components  20  similar to the assembly shown in relation with  FIG. 3B . To achieve this, the electronic component is submitted to a rotation around axis Z by 180 degrees in addition to the rotation of axis Z and of angle “a”. In this case, the component has been submitted to a rotation of axis Z by an angle in the order of 188 degrees. The contact metallizations  3  and  5  of two successive components  20  are adjacent and may be connected by weld or solder electrical connections  15 . 
         [0038]      FIG. 5A  is a top view of a variation  30  of the embodiment of electronic component  20  described in relation with  FIG. 4A . Electronic component  30  comprises the same elements as electronic component  20  but for the fact that contact metallizations  3  and  5  are arranged inside of the circular peripheral edge of the upper surface of the component. Electronic component  30  further comprises two openings  32  and  34 , each of which is adjacent to one of contact metallizations  3  or  5 . 
         [0039]      FIG. 5B  is a top view of an embodiment of a parallel assembly of electronic components  30  of  FIG. 5A . The assembly described herein has the same characteristics as the assembly disclosed in relation with  FIG. 3A  and the same elements are described with the same reference numerals. Components  30  are stacked along a common central axis Z and have been submitted to a rotation about the common central axis Z by a fixed angle “a” with respect to one another. Openings  32  and  34  enable to form the connection of contact metallization  3  of a component with contact metallization  3  of the previous component. The contact metallizations are connected by a weld or solder electrical connection  15 . In this example, the size of openings  32  and  34  only enables to connect two contact metallizations at a time. As a variation, openings  32  and  34  may be enlarged to enable to connect a plurality of contact metallizations at a time. 
         [0040]    Similarly, it is possible to form a series assembly of electronic components  30  similar to the assembly shown in relation with  FIG. 3B . To achieve this, the contact metallization  5  of a component  30  and the contact metallization  3  of the previous component  30  are adjacent and the total rotation angle is in the order of 188 degrees. 
         [0041]    An advantage of this type of assembly is to stack the electronic components with a low bulk and a great stability. 
         [0042]    Specific embodiments have been described. Various alterations, modifications, and improvements will occur to those skilled in the art. In particular, rotation axis Z is not necessarily arranged at the center of the component but may be arranged anywhere on the component surface (for example, the axis Z may instead be positioned at a corner opposite one of the contact metallizations). Further, although the contact metallizations are here shown as having a triangular shape, the contact metallizations may extend on the corner with a different shape, such as a square or oval shape, or also the contact metallizations may be formed on a corner of a component but may not extend all the way to the edge of said component. Finally, although weld or solder electrical connections have been described, any other adapted connection means may be used, for example, connections by a cord of electrically-conductive glue or connections by metal tongues welded, soldered or attached with conductive glue. 
         [0043]    Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and the scope of the present invention. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The present invention is limited only as defined in the following claims and the equivalents thereto.