Stacked microelectronic devices and methods of fabricating same

Abstract

Certain methods of the invention permit spacerless manufacture of stacked microelectronic devices by mechanically supporting a second microelectronic component with a wire coating. This wire coating may be sufficiently adhesive to also mechanically bond the second microelectronic component to a first microelectronic component. Other embodiments of the invention provide spacerless stacked microelectronic devices wherein a second microelectronic component is mechanically supported by a wire coating.

What is claimed is:  
     
         1 . A method of assembling a stacked microelectronic device assembly, comprising: 
 attaching a first microelectronic component to a support, an active surface of the first microelectronic component facing away from a contact surface of the support, the support including a plurality of first electrical contacts and the first microelectronic component including a plurality of second electrical contacts;    electrically connecting a first wire to a first one of the first electrical contacts and to a first one of the second electrical contacts, and electrically connecting a second wire to a second one of the first electrical contacts and to a second one of the second electrical contacts, the first wire being spaced from the second wire;    disposing a wire coating on at least a portion of the first wire and at least a portion of the second wire;    placing at least a portion of a second microelectronic component proximate to the active surface of the first microelectronic component such that the wire coating mechanically supports the second microelectronic component and defines an intercomponent gap between a facing surface of the second microelectronic component and the active surface of the first microelectronic component.    
     
     
         2 . The method of  claim 1  wherein the facing surface of the second microelectronic component has a peripheral portion and a central portion bounded by the peripheral portion; the peripheral portion of the facing surface contacting the coating when the facing surface of the second microelectronic component is placed proximate to the active surface of the first microelectronic component; the central portion overlying the intercomponent gap and remaining exposed prior to further processing.  
     
     
         3 . The method of  claim 2  further comprising encapsulating the first and second microelectronic components in an encapsulant.  
     
     
         4 . The method of  claim 3  wherein the encapsulant is permitted to flow into the intercomponent gap.  
     
     
         5 . The method of  claim 1  further comprising encapsulating the first and second microelectronic components in an encapsulant.  
     
     
         6 . The method of  claim 5  wherein the encapsulant is permitted to flow into the intercomponent gap.  
     
     
         7 . The method of  claim 1  further comprising electrically connecting a third wire to a first one of the third electrical contacts and to a third one of the first electrical contacts  
     
     
         8 . The method of  claim 1  wherein the wire coating comprises a thixotropic material.  
     
     
         9 . The method of  claim 1  wherein the wire coating is initially applied in an uncured state and is partially cured to yield an adhesive, mechanically stable wire coating prior to juxtaposing the facing surface of the second microelectronic component with the active surface of the first microelectronic component.  
     
     
         10 . The method of  claim 9  further comprising further curing the partially cured wire coating after the wire coating mechanically supports the second microelectronic component.  
     
     
         11 . A method of assembling a stacked microelectronic device assembly, comprising: 
 attaching a first microelectronic component to a support, the support including a plurality of first electrical contacts and the first microelectronic component including a plurality of second electrical contacts;    electrically connecting a first one of the first electrical contacts to a first one of the second electrical contacts via a first bonding wire;    electrically connecting a second one of the first electrical contacts to a second one of the second electrical contacts via a second bonding wire, the first one of the second electrical contacts being spaced from the second one of the second electrical contacts;    coating at least a portion of the first bonding wire and at least a portion of the second bonding wire with a wire coating;    partially curing the wire coating;    contacting at least a portion of a second microelectronic component with the wire coating, thereby mechanically supporting the second microelectronic component with respect to the first microelectronic component and defining an intercomponent gap between the first and second microelectronic components; and    electrically connecting a first one of a plurality of third electrical contacts carried by the second microelectronic component to a third one of the first electrical contacts.    
     
     
         12 . The method of  claim 11  wherein the second microelectronic component has a facing surface including a peripheral portion and a central portion bounded by the peripheral portion; the peripheral portion of the facing surface contacting the coating; the central portion overlying the intercomponent gap and remaining exposed when electrically connecting a first one of the third electrical contacts to a third one of the first electrical contacts.  
     
     
         13 . The method of  claim 12  further comprising encapsulating the first and second microelectronic components in an encapsulant and permitting the encapsulant to flow into the intercomponent gap and into contact with the central portion of the facing surface of the second microelectronic component.  
     
     
         14 . The method of  claim 11  further comprising encapsulating the first and second microelectronic components in an encapsulant.  
     
     
         15 . The method of  claim 14  wherein the encapsulant is permitted to flow into the intercomponent gap.  
     
     
         16 . The method of  claim 11  wherein the wire coating comprises a thixotropic material.  
     
     
         17 . The method of  claim 11  wherein the wire coating is initially applied in an uncured state and is partially cured to yield an adhesive, mechanically stable wire coating prior to bringing the second microelectronic component into contact with the wire coating.  
     
     
         18 . The method of  claim 17  further comprising further curing the partially cured wire coating after bringing the second microelectronic component into contact with the wire coating.  
     
     
         19 . A method of assembling a stacked microelectronic device assembly, comprising: 
 attaching a first microelectronic component to a support;    wire bonding a first electrical contact carried by the support to a second electrical contact carried by the first microelectronic component using a first bonding wire;    covering at least a portion of the first bonding wire with a wire coating, the wire coating having an exposed upper surface;    contacting the upper surface of the wire coating with a second microelectronic component, the wire coating mechanically bonding the second microelectronic component to the first microelectronic component; and    electrically connecting a third electrical contact carried by the second microelectronic component to a fourth electrical contact carried by the substrate.    
     
     
         20 . The method of  claim 19  wherein the support includes a plurality of first electrical contacts and the first microelectronic component carries a plurality of second electrical contacts, the first bonding wire being electrically connected to a first one of the first electrical contacts and to a first one of the second electrical contacts.  
     
     
         21 . The method of  claim 20  further comprising wire bonding a second one of the first electrical contacts to a second one of the second electrical contacts using a second bonding wire, the first bonding wire being spaced from the second bonding wire.  
     
     
         22 . The method of  claim 21  further comprising covering at least a portion of the second bonding wire with the wire coating.  
     
     
         23 . The method of  claim 22  wherein the wire coating is applied as a plurality of discrete coatings, a first of the discrete coatings covering the portion of the first bonding wire and a second of the discrete coatings covering the portion of the second bonding wire.  
     
     
         24 . The method of  claim 19  further comprising partially curing the wire coating before contacting the wire coating with the second microelectronic component.  
     
     
         25 . The method of  claim 24  wherein partially curing the wire coating yields an adhesive, mechanically stable coating.  
     
     
         26 . The method of  claim 24  further comprising further curing the partially cured wire coating after contacting the wire coating with the second microelectronic component.  
     
     
         27 . The method of  claim 19  wherein the wire coating contacts a peripheral portion of a facing surface of the second component, a central portion of the facing surface being exposed to an intercomponent gap between the first and second microelectronic components.  
     
     
         28 . The method of  claim 27  further comprising introducing a second material into the intercomponent gap.  
     
     
         29 . The method of  claim 27  wherein the second material comprises an encapsulant having a composition which differs from a composition of the wire coating.  
     
     
         30 . The method of  claim 19  further comprising encapsulating the first and second components in an encapsulant.  
     
     
         31 . The method of  claim 30  wherein the encapsulant has a composition which differs from a composition of the wire coating.  
     
     
         32 . The method of  claim 19  wherein the first and second components define an intercomponent gap therebetween when the upper surface of the wire coating is contacted with the second microelectronic component.  
     
     
         33 . The method of  claim 32  further comprising encapsulating the first and second components in an encapsulant, the encapsulant being introduced into the intercomponent gap.  
     
     
         34 . The method of  claim 19  wherein the wire coating is initially applied as a curable thixotropic coating, the method further comprising at least partially curing the thixotropic coating.  
     
     
         35 . A method of assembling a stacked microelectronic device assembly including a support, a first microelectronic component, and a second microelectronic component; the support carrying a plurality of first electrical contacts, the first microelectronic component carrying a plurality of second electrical contacts, and the second microelectronic component carrying a plurality of third electrical contacts, the method comprising: 
 attaching the first microelectronic component to the substrate and electrically connecting one of the first electrical contacts to one of the second electrical contacts via a first bonding wire;    coating at least a portion of the first bonding wire with a first curable coating;    partially curing the first curable coating, yielding an adhesive, mechanically stable coating;    contacting at least a portion of the second microelectronic component with the adhesive, mechanically stable coating, thereby mechanically supporting the second microelectronic component with respect to the first microelectronic component; and    electrically connecting one of the third electrical contacts to one of the first electrical contacts.    
     
     
         36 . The method of  claim 35  further comprising further curing the adhesive, mechanically stable coating after the second microelectronic component is mechanically supported.  
     
     
         37 . The method of  claim 35  wherein the second microelectronic component has a facing surface including a peripheral portion and a central portion bounded by the peripheral portion; the peripheral portion of the facing surface contacting the coating; the central portion remaining exposed when electrically connecting a first one of the third electrical contacts to a third one of the first electrical contacts.  
     
     
         38 . The method of  claim 37  further comprising encapsulating the first and second microelectronic components in an encapsulant and permitting the encapsulant to flow into contact with the central portion of the facing surface of the second microelectronic component.  
     
     
         39 . The method of  claim 35  further comprising encapsulating the first and second microelectronic components in an encapsulant.  
     
     
         40 . The method of  claim 39  wherein the encapsulant is permitted to flow into an intercomponent gap between the first and second microelectronic components.  
     
     
         41 . The method of  claim 35  wherein the wire coating comprises a thixotropic material.  
     
     
         42 . A stacked microelectronic device, comprising: 
 a support having a plurality of first contacts;    a first microelectronic component carried by the support, the first microelectronic component comprising an active surface having a plurality of second contacts;    a first bonding wire electrically connecting a first one of the first contacts to a first one of the second contacts;    a wire coating covering at least a portion of the first bonding wire;    a second microelectronic component comprising a facing surface and an outer surface, the outer surface having a plurality of third contacts, the facing surface being juxtaposed with the active surface of the first microelectronic component, the wire coating mechanically supporting the second microelectronic component to define an intercomponent gap between the facing surface of the second microelectronic component and the active surface of the first microelectronic component.    
     
     
         43 . The stacked microelectronic device of  claim 42  further comprising a second material within the intercomponent gap, the second material having a different composition from the wire coating.  
     
     
         44 . The stacked microelectronic device of  claim 42  wherein the facing surface of the second microelectronic component has a peripheral portion in supportive contact with the wire coating and an exposed central portion bounded by the peripheral portion.  
     
     
         45 . The stacked microelectronic device of  claim 42  further comprising a second wire electrically connecting a second one of the first electrical contacts to a second one of the second electrical contacts, the second wire being spaced from the first wire.  
     
     
         46 . The stacked microelectronic device of  claim 44  wherein the wire coating also covers at least a portion of the second bonding wire and at least a portion of the active surface of the first microelectronic component, the wire coating contacting both a peripheral portion and a central portion of the facing surface of the second microelectronic component.  
     
     
         47 . The stacked microelectronic device of  claim 42  wherein the wire coating also covers the first one of the first electrical contacts.  
     
     
         48 . A stacked microelectronic device, comprising: 
 a support carrying a plurality of first contacts;    a first microelectronic component carried by the support, the first microelectronic component comprising an active surface bearing a plurality of second contacts;    a first bonding wire electrically connecting a first one of the first contacts to a first one of the second contacts;    a wire coating covering at least a portion of the first bonding wire;    a second microelectronic component comprising a facing surface and an outer surface, the outer surface bearing a plurality of third contacts, the facing surface being juxtaposed with the active surface of the first microelectronic component, the wire coating mechanically supporting the second microelectronic component to define an intercomponent gap between the facing surface of the second microelectronic component and the active surface of the first microelectronic component; and    a deformable adhesive carried in the intercomponent space and adhering the facing surface of the second microelectronic component to the active surface of the first microelectronic component.