Semiconductor chip assembly with post/dielectric/post heat spreader

Abstract

A semiconductor chip assembly includes a semiconductor device, a heat spreader, a conductive trace and first and second adhesives. The heat spreader includes a first post, a second post and a dielectric base. The conductive trace includes a pad and a terminal. The semiconductor device is electrically connected to the conductive trace and thermally connected to the heat spreader. The first post extends from the dielectric base in a first vertical direction into a first opening in the first adhesive, the second post extends from the dielectric base in a second vertical direction into a second opening in the second adhesive and the dielectric base contacts and is sandwiched between and extends laterally from the posts. The conductive trace provides signal routing between the pad and the terminal.

1 . A semiconductor chip assembly, comprising:
 a semiconductor device;   a first adhesive that includes a first opening;   a second adhesive that includes a second opening;   a conductive trace that includes a pad, a terminal and an electrical interconnect in an electrically conductive path between the pad and the terminal; and   a heat spreader that includes a first post, a second post and a dielectric base, wherein (i) the first post extends vertically from the dielectric base in a first vertical direction, (ii) the second post extends vertically from the dielectric base in a second vertical direction opposite the first vertical direction and (iii) the dielectric base is a thermally conductive, electrically insulative material that contacts and is sandwiched between and thermally connects and electrically isolates the posts, covers the first post in the second vertical direction, covers the second post in the first vertical direction and extends laterally from the posts in lateral directions orthogonal to the vertical directions;   wherein the semiconductor device is mounted on the first post, extends vertically beyond the dielectric base in the first vertical direction, extends laterally within peripheries of the posts, is electrically connected to the pad and thereby electrically connected to the terminal, is thermally connected to the first post and thereby thermally connected to the second post and is electrically isolated from the second post;   wherein the first adhesive extends vertically beyond the dielectric base in the first vertical direction, extends laterally from the first post to or beyond the terminal and is sandwiched between the dielectric base and the pad;   wherein the second adhesive extends vertically beyond the dielectric base in the second vertical direction, extends laterally from the second post to or beyond the terminal and is sandwiched between the dielectric base and the terminal;   wherein the pad extends vertically beyond the dielectric base in the first vertical direction, the terminal extends vertically beyond the dielectric base in the second vertical direction and the electrical interconnect extends through the dielectric base and the adhesives; and   wherein the first post extends into the first opening, the second post extends into the second opening and the dielectric base contacts and is sandwiched between the adhesives and covers the semiconductor device in the second vertical direction.   
     
     
         2 . The assembly of  claim 1 , wherein the semiconductor device is an LED chip. 
     
     
         3 . The assembly of  claim 1 , wherein the semiconductor device is electrically connected to the pad using a wire bond and is thermally connected to the first post using a die attach. 
     
     
         4 . The assembly of  claim 1 , wherein the first adhesive contacts the first post and is spaced from the second post and the second adhesive contacts the second post and is spaced from the first post. 
     
     
         5 . The assembly of  claim 1 , wherein the first adhesive covers and surrounds the first post in the lateral directions and the second adhesive covers and surrounds the second post in the lateral directions. 
     
     
         6 . The assembly of  claim 1 , wherein the first adhesive extends to peripheral edges of the assembly and the second adhesive extends to peripheral edges of the assembly. 
     
     
         7 . The assembly of  claim 1 , wherein the first adhesive is coplanar with the first post between opposing lateral surfaces of the pad and the second adhesive is coplanar with the second post between opposing lateral surfaces of the terminal. 
     
     
         8 . The assembly of  claim 1 , wherein the first post has a diameter that decreases as it extends vertically from the dielectric base in the first vertical direction and the second post has a diameter that decreases as it extends vertically from the dielectric base in the second vertical direction. 
     
     
         9 . The assembly of  claim 1 , wherein the first post has tapered sidewalls characteristic of wet chemical etching and the second post has tapered sidewalls characteristic of wet chemical etching. 
     
     
         10 . The assembly of  claim 1 , wherein the dielectric base is (i) epoxy filled with aluminum oxide or aluminum nitride, (ii) polyimide filled with aluminum oxide or aluminum nitride, or (iii) diamond-like carbon. 
     
     
         11 . The assembly of  claim 1 , wherein the dielectric base extends to peripheral edges of the assembly. 
     
     
         12 . The assembly of  claim 1 , wherein the pad extends beyond the first adhesive in the first vertical direction and the terminal extends beyond the second adhesive in the second vertical direction. 
     
     
         13 . The assembly of  claim 1 , wherein the pad contacts the first adhesive and the terminal contacts the second adhesive. 
     
     
         14 . The assembly of  claim 1 , wherein the pad and the terminal are spaced from the adhesives, a first dielectric layer contacts and is sandwiched between the pad and the first adhesive and is spaced from the first post and the dielectric base, a second dielectric layer contacts and is sandwiched between the terminal and the second adhesive and is spaced from the second post and the dielectric base, the first post extends into a first aperture in the first dielectric layer, the second post extends through a second aperture in the second dielectric layer and the electrical interconnect extends through the dielectric layers. 
     
     
         15 . The assembly of  claim 1 , wherein the electrical interconnect is a plated through-hole. 
     
     
         16 . The assembly of  claim 1 , wherein the posts are the same metal and the pad and the terminal are the same metals. 
     
     
         17 . The assembly of  claim 1 , wherein the pad and the terminal include a gold, silver or nickel surface layer and a buried copper core and are primarily copper, the posts include copper and the dielectric base includes plastic. 
     
     
         18 . The assembly of  claim 1 , wherein the conductive trace includes a copper core shared by the pad, the terminal and the electrical interconnect. 
     
     
         19 . The assembly of  claim 1 , wherein the heat spreader includes:
 a first cap that is adjacent to the first post, covers the first post in the upward direction and extends laterally from the first post and that contacts the first adhesive and extends beyond the first adhesive in the first vertical direction; and   a second cap that is adjacent to the second post, covers the second post in the downward direction and extends laterally from the second post and that contacts the second adhesive and extends beyond the second adhesive in the second vertical direction.   
     
     
         20 . The assembly of  claim 19 , wherein:
 the pad and the first cap have the same thickness where closest to one another and are coplanar with one another at a first surface that faces in the first vertical direction; and   the terminal and the second cap have the same thickness where closest to one another and are coplanar with one another at a second surface that faces in the second vertical direction.   
     
     
         21 . A semiconductor chip assembly, comprising:
 a semiconductor device;   a first adhesive that includes a first opening;   a second adhesive that includes a second opening;   a conductive trace that includes a pad, a terminal and an electrical interconnect, wherein the electrical interconnect includes a plated through-hole in an electrically conductive path between the pad and the terminal; and   a heat spreader that includes a first post, a second post, a first cap, a second cap and a dielectric base, wherein (i) the first post extends vertically from the dielectric base in a first vertical direction, (ii) the second post extends vertically from the dielectric base in a second vertical direction opposite the first vertical direction, (iii) the first cap is adjacent to the first post, covers the first post in the first vertical direction and extends laterally from the first post, (iv) the second cap is adjacent to the second post, covers the second post in the second vertical direction and extends laterally from the second post and (v) the dielectric base is a thermally conductive, electrically insulative material that contacts and is sandwiched between and thermally connects and electrically isolates the posts, covers the first post in the second vertical direction, covers the second post in the first vertical direction and extends laterally from the posts and laterally beyond the caps in lateral directions orthogonal to the vertical directions;   wherein the semiconductor device is mounted on the first cap, extends vertically beyond the first cap and the first adhesive in the first vertical direction, extends laterally within peripheries of the posts, is located within peripheries of the caps, is electrically connected to the pad and thereby electrically connected to the terminal, is thermally connected to the first cap and thereby thermally connected to the second cap and is electrically isolated from the second cap;   wherein the first adhesive contacts the first post, the first cap and the dielectric base, is spaced from the second post and the second cap, extends vertically beyond the dielectric base in the first vertical direction, extends laterally from the first post to or beyond the terminal and is sandwiched between the dielectric base and the pad;   wherein the second adhesive contacts the second post, the second cap and the dielectric base, is spaced from the first post and the first cap, extends vertically beyond the dielectric base in the second vertical direction, extends laterally from the second post to or beyond the terminal and is sandwiched between the dielectric base and the terminal;   wherein the pad extends vertically beyond the first adhesive in the first vertical direction, the terminal extends vertically beyond the second adhesive in the second vertical direction and the plated through-hole extends through the dielectric base and the adhesives;   wherein the first post extends into the first opening, the second post extends into the second opening, the first cap extends vertically beyond the first adhesive in the first vertical direction, the second cap extends vertically beyond the second adhesive in the second vertical direction and the dielectric base is sandwiched between the adhesives and covers the semiconductor device in the second vertical direction; and   wherein the posts and the caps are metallic, the dielectric base and the adhesives are non-metallic and extend to peripheral edges of the assembly, the caps are electrically isolated from one another and the second cap has no electrical function.   
     
     
         22 . The assembly of  claim 21 , wherein the semiconductor device is an LED chip, is mounted on the first cap using a die attach, is electrically connected to the pad using a wire bond and is thermally connected to the first cap using the die attach. 
     
     
         23 . The assembly of  claim 21 , wherein the first adhesive covers and surrounds the first post in the lateral directions and the second adhesive covers and surrounds the second post in the lateral directions. 
     
     
         24 . The assembly of  claim 21 , wherein the first adhesive is coplanar with the first post at the first cap between opposing lateral surfaces of the pad and at the dielectric base and the second adhesive is coplanar with the second post at the second cap between opposing lateral surfaces of the terminal and at the dielectric base. 
     
     
         25 . The assembly of  claim 21 , wherein the adhesives are spaced from one another. 
     
     
         26 . The assembly of  claim 21 , wherein the first post has a diameter that decreases as it extends vertically from the dielectric base in the first vertical direction and the second post has a diameter that decreases as it extends vertically from the dielectric base in the second vertical direction. 
     
     
         27 . The assembly of  claim 21 , wherein the first post has tapered sidewalls characteristic of wet chemical etching and the second post has tapered sidewalls characteristic of wet chemical etching. 
     
     
         28 . The assembly of  claim 21 , wherein the dielectric base is (i) epoxy filled with aluminum oxide or aluminum nitride, (ii) polyimide filled with aluminum oxide or aluminum nitride, or (iii) diamond-like carbon. 
     
     
         29 . The assembly of  claim 21 , wherein the pad contacts the first adhesive and the terminal contacts the second adhesive. 
     
     
         30 . The assembly of  claim 21 , wherein the pad and the terminal are spaced from the adhesives, a first dielectric layer contacts and is sandwiched between the pad and the first adhesive, contacts the first cap and is spaced from the first post and the dielectric base, a second dielectric layer contacts and is sandwiched between the terminal and the second adhesive, contacts the second cap and is spaced from the second post and the dielectric base, the first post extends through a first aperture in the first dielectric layer, the second post extends through a second aperture in the second dielectric layer and the plated through-hole extends through the dielectric layers. 
     
     
         31 . The assembly of  claim 21 , wherein the pad is located within the periphery of the second post. 
     
     
         32 . The assembly of  claim 21 , wherein the first post has a surface area that is less than one-half of a surface area of the second post. 
     
     
         33 . The assembly of  claim 21 , wherein the pad and the first cap have the same thickness where closest to one another and are coplanar with one another at a first surface that faces in the first vertical direction. 
     
     
         34 . The assembly of  claim 21 , wherein the pad and the first cap have the same thickness where closest to one another, have different thickness where the first cap is adjacent to the first post and are coplanar with one another at a first surface that faces in the first vertical direction. 
     
     
         35 . The assembly of  claim 21 , wherein the terminal and the second cap have the same thickness where closest to one another and are coplanar with one another at a second surface that faces in the second vertical direction. 
     
     
         36 . The assembly of  claim 21 , wherein the terminal and the second cap have the same thickness where closest to one another, have different thickness where the second cap is adjacent to the second post and are coplanar with one another at a second surface that faces in the second vertical direction. 
     
     
         37 . The assembly of  claim 21 , wherein:
 the pad and the first cap have the same thickness where closest to one another, have different thickness where the first cap is adjacent to the first post and are coplanar with one another at a first surface that faces in the first vertical direction; and   the terminal and the second cap have the same thickness where closest to one another, have different thickness where the second cap is adjacent to the second post and are coplanar with one another at a second surface that faces in the second vertical direction.   
     
     
         38 . The assembly of  claim 21 , wherein the posts are the same metal and the pad, the terminal and the caps are the same metals. 
     
     
         39 . The assembly of  claim 21 , wherein the pad, the terminal and the caps include a gold, silver or nickel surface layer and a buried copper core and are primarily copper, the posts are copper, the plated through-hole includes copper and the dielectric base includes plastic. 
     
     
         40 . The assembly of  claim 21 , wherein the conductive trace includes a copper core shared by the pad, the terminal and the plated through-hole. 
     
     
         41 . A semiconductor chip assembly, comprising:
 a semiconductor device;   a first adhesive that includes a first opening;   a second adhesive that includes a second opening;   a heat spreader that includes a first post, a second post, a first cap, a second cap and a dielectric base, wherein (i) the first post extends vertically from the dielectric base in a first vertical direction, (ii) the second post extends vertically from the dielectric base in a second vertical direction opposite the first vertical direction, (iii) the first cap is adjacent to the first post, covers the first post in the first vertical direction and extends laterally from the first post, (iv) the second cap is adjacent to the second post, covers the second post in the second vertical direction and extends laterally from the second post and (v) the dielectric base is a thermally conductive, electrically insulative material that contacts and is sandwiched between and thermally connects and electrically isolates the posts, covers the first post in the second vertical direction, covers the second post in the first vertical direction and extends laterally from the posts and laterally beyond the caps in lateral directions orthogonal to the vertical directions;   a first conductive trace that includes a pad, a first terminal and a first electrical interconnect, wherein the first electrical interconnect includes a first plated through-hole in an electrically conductive path between the pad and the first terminal; and   a second conductive trace that includes the first cap, a second terminal and a second electrical interconnect, wherein the second electrical interconnect includes a second plated through-hole in an electrically conductive path between the first cap and the second terminal;   wherein the semiconductor device is mounted on the first cap, extends vertically beyond the first cap and the first adhesive in the first vertical direction, extends laterally within peripheries of the posts, is located within peripheries of the caps, is electrically connected to the pad and thereby electrically connected to the first terminal, is electrically connected to the first cap and thereby electrically connected to the second terminal, is thermally connected to the first cap and thereby thermally connected to the second cap and is electrically isolated from the second post and the second cap;   wherein the first adhesive contacts the first post, the first cap and the dielectric base, is spaced from the second post and the second cap, extends vertically beyond the dielectric base in the first vertical direction, extends laterally from the first post to or beyond the terminals and is sandwiched between the dielectric base and the pad;   wherein the second adhesive contacts the second post, the second cap and the dielectric base, is spaced from the first post and the first cap, extends vertically beyond the dielectric base in the second vertical direction, extends laterally from the second post to or beyond the terminals and is sandwiched between the dielectric base and the terminals;   wherein the pad extends vertically beyond the first adhesive in the first vertical direction, the terminals extend vertically beyond the second adhesive in the second vertical direction and the plated through-holes extend through the dielectric base and the adhesives;   wherein the first post extends into the first opening, the second post extends into the second opening, the first cap extends vertically beyond the first adhesive in the first vertical direction, the second cap extends vertically beyond the second adhesive in the second vertical direction and the dielectric base is sandwiched between the adhesives and covers the semiconductor device in the second vertical direction; and   wherein the posts and the caps are metallic and spaced from peripheral edges of the assembly, the dielectric base and the adhesives are non-metallic and extend to peripheral edges of the assembly, the posts are electrically isolated from one another, the caps are electrically isolated from one another, the terminals are electrically isolated from one another and the second cap has no electrical function and electrically floats during operation of the semiconductor device.   
     
     
         42 . The assembly of  claim 41 , wherein the semiconductor device is a vertical LED chip, is mounted on the first cap using a die attach, is electrically connected to the pad using a wire bond and is electrically and thermally connected to the first cap using the die attach. 
     
     
         43 . The assembly of  claim 41 , wherein the first adhesive covers and surrounds the first post in the lateral directions and is coplanar with the first post at the first cap between opposing lateral surfaces of the pad and at the dielectric base, the second adhesive covers and surrounds the second post in the lateral directions and is coplanar with the second post at the second cap between opposing lateral surfaces of the first terminal and between opposing lateral surfaces of the second terminal and at the dielectric base and the adhesives are spaced from one another. 
     
     
         44 . The assembly of  claim 41 , wherein the first post has a diameter that decreases as it extends vertically from the dielectric base in the first vertical direction and has tapered sidewalls characteristic of wet chemical etching and the second post has a diameter that decreases as it extends vertically from the dielectric base in the second vertical direction and has tapered sidewalls characteristic of wet chemical etching. 
     
     
         45 . The assembly of  claim 41 , wherein the pad contacts the first adhesive and the terminals contact the second adhesive. 
     
     
         46 . The assembly of  claim 41 , wherein the pad and the terminals are spaced from the adhesives, a first dielectric layer contacts and is sandwiched between the pad and the first adhesive, contacts the first cap and is spaced from the first post and the dielectric base, a second dielectric layer contacts and is sandwiched between the terminals and the second adhesive, contacts the second cap and is spaced from the second post and the dielectric base, the first post extends through a first aperture in the first dielectric layer, the second post extends through a second aperture in the second dielectric layer and the plated through-holes extend through the dielectric layers. 
     
     
         47 . The assembly of  claim 41 , wherein:
 the pad and the first cap have the same thickness where closest to one another, have different thickness where the first cap is adjacent to the first post and are coplanar with one another at a first surface that faces in the first vertical direction;   the first terminal and the second cap have the same thickness where closest to one another, have different thickness where the second cap is adjacent to the second post and are coplanar with one another at a second surface that faces in the second vertical direction; and   the second terminal and the second cap have the same thickness where closest to one another, have different thickness where the second cap is adjacent to the second post and are coplanar with one another at the second surface.   
     
     
         48 . The assembly of  claim 41 , wherein the posts are the same metal and the pad, the terminals and the caps are the same metals. 
     
     
         49 . The assembly of  claim 41 , wherein the pad, the terminals and the caps include a gold, silver or nickel surface layer and a buried copper core and are primarily copper, the posts are copper, the plated through-holes include copper and the dielectric base includes plastic. 
     
     
         50 . The assembly of  claim 41 , wherein the conductive trace includes a copper core shared by the pad, the first terminal and the first plated through-hole and the heat spreader includes a copper core shared by the first post, the first cap, the second plated through-hole and the second terminal.