Microelectronic assemblies incorporating inductors

Abstract

Inductors are provided in chip assemblies such as in packaged semiconductor chips. The inductors may be incorporated in a chip carrier which forms part of the package, and may include, for example, spiral or serpentine inductors formed from traces on the chip carrier. The chip carrier may include a flap bearing the inductive element, and this flap may be bent to tilt the inductive element out of the plane of the chip carrier to reduce electromagnetic interaction between the inductive element and surrounding electrical components. Other inductors include solenoids formed in part by leads on the chip carrier as, for example, by displacing leads out of the plane of the chip carrier to form loops in vertically-extensive planes transverse to the plane of the chip carrier. Additional features provide trimming of the inductor to a desired inductance value during by breaking or connecting leads during assembly.

1 . A component for making a microelectronic assembly including: 
 (a) a substrate including a metallic layer including a ferromagnetic material, a first dielectric layer on one side of said metallic layer, a second dielectric layer on the opposite side of said metallic layer and a plurality of vias extending through said metallic layer and said first and second dielectric layers;    (b) a plurality of first conductors on said first dielectric layer; and    (c) a plurality of second conductors on said second dielectric layer, at least some of said first and second conductors being connected in series with one another to so as to form a solenoidal inductor including plurality of loops, each such loop including one said first conductor and one said second conductor, at least some of said loops surrounding at least a part of said ferromagnetic material so that the surrounded ferromagnetic material constitutes a ferromagnetic core for said solenoidal inductor.    
   
   
       2 . A component as claimed in  claim 1  wherein said substrate is flexible.  
   
   
       3 . A component as claimed in  claim 2  wherein said first and second dielectric layers are formed as coatings on said metallic layer.  
   
   
       4 . A component as claimed in  claim 2  further comprising connection elements for connecting said inductor to a semiconductor chip separate from said component.  
   
   
       5 . A component for making a microelectronic assembly comprising: 
 (a) a substrate including a dielectric layer having first and second sides;    (b) a plurality of first side conductors on said first side of said dielectric layer;    (c) a plurality of second side conductors on said second side of said dielectric layer;    (d) a plurality of first loop conductors, each said first loop conductor extending from one of said first side conductors to another one of said first side conductors and projecting away from said substrate on the first side of said dielectric layer so that said first loop conductors and said first side conductors cooperatively form a first solenoid; and    (e) a plurality of second loop conductors, each said second loop conductor extending from one of said second side conductors to another one of said second side conductors, each said second loop conductor projecting away from said substrate on the first side of said dielectric layer so that said second loop conductors and said second side conductors cooperatively form a second solenoid surrounding said first solenoid.    
   
   
       6 . A component for making a microelectronic assembly comprising: 
 (a) a substrate including a dielectric layer; and    (b) a plurality of conductive elements arrayed on said substrate along a path, each such conductive element extending transverse to said path, said substrate having bond windows on opposite sides of said path, each said conductive element including a first lead portion aligned with one said bond window on one side of said path, a second lead portion aligned with another said bond window on the other side of said path and a trace portion extending between the first and second lead portions.    
   
   
       7 . A microelectronic assembly comprising a component as claimed in  claim 6  and a chip having a front face and a plurality of conductive units, each said conductive unit of said chip including a first contact exposed on said front face, a second contact exposed on said front face and a conductor extending between such first and second contacts, said substrate overlying said front face of said chip, said lead portions being connected to said contacts so as to form a solenoid including a plurality of turns connected in series and arrayed along said path, each turn including one said conductive element of said component and one said conductive unit of said chip.  
   
   
       8 . A method of making a solenoid comprising the step of assembling a component as claimed in  claim 6 , to a chip having conductive units, each having first and second contacts, and bonding the lead portions of the conductive elements to the first contacts on the chip and the second lead portions to the second contacts on the chip so that the first and second lead portions of each conductive element are connected to different conductive units on the chip.  
   
   
       9 . A microelectronic assembly comprising: 
 (a) a dielectric element extending generally in a first horizontal plane and having a first window extending at least partially through the dielectric element;    (b) a plurality of leads extending across the window, said leads being spaced apart from one another along a horizontal path, said leads including first and second sets of leads interspersed with one another along the path and connected in series with one another, at least one said lead of said second set being offset at said window in a vertical direction from at least one adjacent lead of said first set so as to form one or more vertically-extensive turns, each such turn including at least one lead of said first set and at least one lead of said second set.    
   
   
       10 . An assembly as claimed in  claim 9  further comprising a substrate disposed below said leads of said first set, said leads of said second set being attached to said substrate.  
   
   
       11 . An assembly as claimed in  claim 10  wherein said substrate includes one or more electrically conductive pads, at least some of said leads of said second set being electrically connected to said pads.  
   
   
       12 . An assembly as claimed in  claim 11  wherein at least one lead of said second set includes a first and second lead portions separate from one another extending from opposite sides of said window to one of said pads, such first and second lead portions being connected to one another by said one of said pads.  
   
   
       13 . An assembly as claimed in  claim 9  further comprising traces on said dielectric element, said traces interconnecting said leads with one another in said series.  
   
   
       14 . An assembly as claimed in  claim 9  further comprising an encapsulant at least partially surrounding said leads.  
   
   
       15 . An assembly as claimed in  claim 14  wherein said encapsulant includes a ferromagnetic material.  
   
   
       16 . An assembly as claimed in  claim 10  wherein said substrate includes a chip.  
   
   
       17 . An assembly as claimed in  claim 16  wherein said chip incorporates at least one passive component selected from the group consisting of resistors and capacitors.  
   
   
       18 . A component for making electronic assemblies including inductors, said component comprising: 
 (a) a dielectric element having a first window therein extending at least partially through the dielectric element, said first window having a lengthwise direction;    (b) first and second sets of leads, said leads extending at least partially across said first window substantially in a horizontal plane, said leads of said first and second sets being interspersed with one another along the lengthwise direction of the window, said leads of said second set being displaceable in a vertical direction relative to said dielectric element and said leads of said first set; and    (c) conductors interconnecting said leads of said first and second sets in series with one another.    
   
   
       19 . A component as claimed in  claim 18  wherein at least some of said leads of said second set include frangible sections.  
   
   
       20 . A component as claimed in  claim 18  wherein at least some of said leads of said second set include first and second lead portions, each said first portion having an anchor end affixed to said dielectric element at a first side of said window and a displaceable end remote from such first side, each said second portion having an anchor end affixed to said dielectric element at a second side of said window and a displaceable end remote from such second side.  
   
   
       21 . A component as claimed in  claim 18  wherein at least some of said leads of said second set are curved in said horizontal plane.  
   
   
       22 . A component as claimed in  claim 18  wherein at least some of said leads of said second set have first and second ends mounted to the dielectric element on first and second sides thereof so that said first and second ends define a twist axis, and have displaceable sections offset in a horizontal direction from said twist axis.  
   
   
       23 . A component as claimed in  claim 18  wherein said dielectric element has terminals thereon adapted for surface mounting to a circuit board.  
   
   
       24 . A microelectronic assembly including: 
 (a) a substrate having one or more pads thereon;    (b) a dielectric element overlying the substrate and having one or more windows aligned with said one or more pads;    (c) a plurality of conductors on said dielectric element, said conductors including a first pair of said conductors connected to a first one of said pads in a first one of said windows and interconnected to one another through said first one of said pads, said conductors cooperatively defining an inductor including said first pair of said conductors.    
   
   
       25 . An assembly as claimed in  claim 24  wherein said conductors include first and second main conductors each having proximal and distal ends, said first pair of conductors and said first one of said pads providing a conductive path between said main conductors at a first location between the proximal and distal ends of the main conductors.  
   
   
       26 . An assembly as claimed in  claim 25  wherein said conductive path between said first pair of conductors and said first pad constitutes the only direct conductive path between said first and second main conductors.  
   
   
       27 . An assembly as claimed in  claim 25  wherein said conductors include a plurality of first cross-conductor sections connected to the first main conductor, and a plurality of second cross-connector sections connected to the second main conductor, and wherein said first pair of conductors includes one of said first cross-conductor sections and one of said second cross-connector sections, at least some of said cross-connector sections not being connected in a direct conductive path between said first and second main conductors.  
   
   
       28 . An assembly as claimed in  claim 25  wherein said conductors include trace portions on said dielectric element and lead portions formed integrally with said trace portions, said first pair of conductors including two of said lead portions bonded to said first one of said pads.  
   
   
       29 . An assembly as claimed in  claim 25  wherein said substrate includes a chip.  
   
   
       30 . An assembly as claimed in  claim 29  wherein said chip incorporates at least one passive component selected from the group consisting of resistors and capacitors.  
   
   
       31 . An assembly as claimed in  claim 29  wherein said dielectric element has terminals thereon adapted for surface mounting to a circuit board.