Integrated circuits protected by substrates with cavities, and methods of manufacture

Abstract

Dies ( 110 ) with integrated circuits are attached to a wiring substrate ( 120 ), possibly an interposer, and are protected by a protective substrate ( 410 ) attached to a wiring substrate. The dies are located in cavities in the protective substrate (the dies may protrude out of the cavities). In some embodiments, each cavity surface puts pressure on the die to strengthen the mechanical attachment of the die the wiring substrate, to provide good thermal conductivity between the dies and the ambient (or a heat sink), to counteract the die warpage, and possibly reduce the vertical size. The protective substrate may or may not have its own circuitry connected to the dies or to the wiring substrate. Other features are also provided.

1 . A manufacture comprising:
 (a) a structure comprising:   a first substrate comprising one or more first contact pads; and   one or more dies attached to the first substrate, each die comprising a semiconductor integrated circuit which comprises one or more contact pads each of which is attached to a respective first contact pad;   wherein the first structure comprises a region of a first material;   (b) a second substrate comprising one or more cavities in the bottom, an entire bottom surface of the second substrate being made of a second material, the second substrate being attached to said structure, wherein at least part of each die is located in a corresponding cavity in the second substrate;   wherein said region underlies the second substrate, and in top view said region reaches an outer lateral boundary of the second substrate and also reaches at least one of the one or more dies;   wherein the first material is or is not the same as the second material and has substantially the same coefficient of thermal expansion (CTE) as the second material;   wherein said region is directly bonded to the bottom surface of the second substrate to physically contact the bottom surface of the second substrate;   wherein at least a first cavity of the one or more cavities comprises an encapsulant which fills the first cavity over each die at least partially located in the first cavity but a top surface of the encapsulant is not attached to a top surface of the first cavity.   
     
     
         2 . The manufacture of  claim 1  wherein the bottom surface of the second substrate comprises a surface area attached to said structure, and said surface area laterally surrounds each cavity. 
     
     
         3 . The manufacture of  claim 32  wherein the at least one die is attached to the surface of the corresponding cavity. 
     
     
         4 . The manufacture of  claim 32  wherein the at least one die is not attached to the surface of the corresponding cavity. 
     
     
         5 . The manufacture of  claim 1  wherein:
 the first substrate comprises one or more second contact pads at a bottom side of the first substrate; and 
 the first substrate comprises one or more electrically conductive paths passing through the first substrate and electrically connecting at least one first contact pad to at least one second contact pad. 
 
     
     
         6 . The manufacture of  claim 32  wherein at least one of the conditions (A) and (B) is satisfied at room temperature. 
     
     
         7 - 24 . (canceled) 
     
     
         25 . The manufacture of  claim 1  wherein for at least one cavity, each die in the cavity has substantially the same CTE as the first and second materials. 
     
     
         26 . The manufacture of  claim 1  wherein the entire second substrate is made of the second material. 
     
     
         27 . The manufacture of  claim 1  wherein at least one of the first and second materials is semiconductor. 
     
     
         28 . The manufacture of  claim 1  further comprising an encapsulant covering and physically contacting each die, the encapsulant being a molding compound, wherein none of the first and second materials is a molding compound. 
     
     
         29 . The manufacture of  claim 1  wherein the first region is part of the first substrate. 
     
     
         30 . The manufacture of  claim 1  wherein the second substrate has a first thickness except at a location of each cavity, the second substrate being thinner at the location of each cavity than the first thickness. 
     
     
         31 . The manufacture of  claim 1  wherein the second substrate is thinner over each cavity than at a location not overlying any one of the one or more cavities. 
     
     
         32 . The manufacture of  claim 1  wherein at least at some temperature at which the structure is electrically operable, at least one die satisfies one or both of conditions (A) and (B):
 (A) the die physically contacts a surface of the corresponding cavity; 
 (B) the die is separated from the surface of the corresponding cavity by solid material which physically contacts the die and the surface of the corresponding cavity. 
 
     
     
         33 . A manufacture comprising:
 (a) a structure comprising:   a first substrate comprising one or more first contact pads; and   one or more dies attached to the first substrate, each die comprising a semiconductor integrated circuit which comprises one or more contact pads each of which is attached to a respective first contact pad;   wherein the first structure comprises a region of a predefined material;   (b) a second substrate comprising one or more cavities in the bottom, an entire bottom surface of the second substrate being made of the predefined material, the second substrate being attached to said structure, wherein at least part of each die is located in a corresponding cavity in the second substrate;   wherein said region underlies the second substrate, and in top view said region reaches an outer lateral boundary of the second substrate and also reaches at least one of the one or more dies;   wherein said region is directly bonded to the bottom surface of the second substrate to physically contact the bottom surface of the second substrate;   wherein in at least a first cavity of the one or more cavities, for at least one die at least partially located in the first cavity, the die is attached to a top surface of the first cavity without a molding compound between the die and the top surface of the first cavity.   
     
     
         34 . The manufacture of  claim 33  wherein at least at some temperature at which the structure is electrically operable, at least one die satisfies one or both of conditions (A) and (B):
 (A) the die physically contacts a surface of the corresponding cavity; 
 (B) the die is separated from the surface of the corresponding cavity by solid material which physically contacts the die and the surface of the corresponding cavity. 
 
     
     
         35 . The manufacture of  claim 33  wherein said region is part of the first substrate. 
     
     
         36 . A manufacture comprising:
 (a) a first substrate comprising:   a first body made of a first material;   one or more conductive vias each of which passes through the first body between a top surface and a bottom surface of the first body;   a redistribution layer comprising one or more conductive lines and dielectric which is not the first material; and   one or more first contact pads at a top of the redistribution layer and spaced from the first body, the one or more conductive lines interconnecting one or more of the one or more conductive vias and one or more of the one or more first contact pads;   (b) one or more dies attached to the first substrate, each die comprising a semiconductor integrated circuit which comprises one or more contact pads each of which is attached to a respective first contact pad;   (c) a second substrate comprising a second body made from a second material which is or is not the same as the first material, the second substrate comprising one or more cavities in the bottom, each cavity extending into the second body, the second body being thinner above each cavity than at a location not overlying any one of the one or more cavities, the second substrate comprising a bottom surface comprising an area which lies outside of the one or more cavities and is directly bonded to a top surface of the redistribution layer to physically contact the top surface of the redistribution layer;   wherein the first material has substantially the same coefficient of thermal expansion (CTE) as the second material;   wherein in at least a first cavity of the one or more cavities, for at least one die at least partially located in the first cavity, the die is attached to a top surface of the first cavity without a molding compound between the die and the top surface of the first cavity.   
     
     
         37 . The manufacture of  claim 36  wherein the first material is the same as the second material. 
     
     
         38 . The manufacture of  claim 36  wherein at least one of the first and second materials is semiconductor.