Method of making a semiconductor chip assembly with a post/base/flange heat spreader and a cavity in the flange

Abstract

A method of making a semiconductor chip assembly includes providing a post and a base, mounting an adhesive on the base including inserting the post into an opening in the adhesive, mounting a first conductive layer on the adhesive including aligning the post with an aperture in the first conductive layer, then flowing the adhesive between the post and the first conductive layer, solidifying the adhesive, then etching the post to form a first cavity in the adhesive above the post, depositing a second conductive layer into the first cavity to form a second cavity that extends into the first cavity, providing a conductive trace that includes a pad, a terminal and a selected portion of the first conductive layer, providing a heat spreader that includes the post, the base and a flange that includes a selected portion of the second conductive layer that defines the second cavity, mounting a semiconductor device on the flange in the second cavity, electrically connecting the semiconductor device to the conductive trace and thermally connecting the semiconductor device to the heat spreader.

1 - 35 . (canceled) 
     
     
         36 . A method of making a semiconductor chip assembly, comprising:
 providing a post, a base, an adhesive and a first conductive layer, wherein
 the post is adjacent to the base, extends above the base in an upward direction, extends into an opening in the adhesive and is aligned with an aperture in the first conductive layer, 
 the base extends below the post in a downward direction opposite the upward direction and extends laterally from the post in lateral directions orthogonal to the upward and downward directions, 
 the adhesive is mounted on and extends above the base, is sandwiched between the base and the first conductive layer and is non-solidified, and 
 the first conductive layer is mounted on and extends above the adhesive; then 
   flowing the adhesive into and upward in a gap located in the aperture between the post and the first conductive layer;   solidifying the adhesive; then   etching the post, thereby forming a first cavity in the adhesive that is located above and extends to the post and faces in the upward direction;   depositing a second conductive layer on the post and the adhesive in the first cavity, thereby forming a second cavity that extends into the first cavity, is located above and spaced from the post, is spaced from the adhesive and faces in the upward direction; then   providing a conductive trace that includes a pad, a terminal and selected portions of the conductive layers;   providing a heat spreader that includes the post, the base and a flange, wherein the flange includes a selected portion of the second conductive layer that defines the second cavity; then   mounting a semiconductor device on the flange, wherein the semiconductor device overlaps the post and extends into the second cavity;   electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and   thermally connecting the semiconductor device to the flange, thereby thermally connecting the semiconductor device to the post, thereby thermally connecting the semiconductor device to the base.   
     
     
         37 . The method of  claim 36 , wherein providing the post and the base includes:
 providing a metal plate;   forming an etch mask on the metal plate that selectively exposes the metal plate and defines the post; and   etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess and the base includes an unetched portion of the metal plate below the post and the recess.   
     
     
         38 . The method of  claim 36 , wherein:
 providing the adhesive includes providing a prepreg with uncured epoxy;   flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the first conductive layer; and   solidifying the adhesive includes curing the uncured epoxy.   
     
     
         39 . The method of  claim 36 , wherein flowing the adhesive includes filling the gap with the adhesive. 
     
     
         40 . The method of  claim 36 , wherein mounting the first conductive layer includes mounting the first conductive layer alone on the adhesive. 
     
     
         41 . The method of  claim 36 , wherein mounting the first conductive layer includes mounting the first conductive layer and a dielectric layer on the adhesive. 
     
     
         42 . The method of  claim 36 , wherein providing the pad includes removing selected portions of the conductive layers after solidifying the adhesive. 
     
     
         43 . The method of  claim 36 , wherein providing the flange includes removing selected portions of the conductive layers. 
     
     
         44 . The method of  claim 36 , wherein providing the terminal includes removing selected portions of the base. 
     
     
         45 . The method of  claim 36 , wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the flange, electrically connecting the semiconductor device includes providing a wire bond between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the die attach between the semiconductor device and the flange. 
     
     
         46 . A method of making a semiconductor chip assembly, comprising:
 providing a post and a base, wherein the post is adjacent to and integral with the base and extends above the base in an upward direction, and the base extends below the post in a downward direction opposite the upward direction and extends laterally from the post in lateral directions orthogonal to the upward and downward directions;   providing an adhesive, wherein an opening extends through the adhesive;   providing a first conductive layer, wherein an aperture extends through the first conductive layer;   mounting the adhesive on the base, including inserting the post into the opening, wherein the adhesive extends above the base and the post extends into the opening;   mounting the first conductive layer on the adhesive, including aligning the post with the aperture, wherein the first conductive layer extends above the adhesive and the adhesive is sandwiched between the base and the first conductive layer and is non-solidified; then   applying heat to melt the adhesive;   moving the base and the first conductive layer towards one another, thereby moving the post upward in the aperture and applying pressure to the molten adhesive between the base and the first conductive layer, wherein the pressure forces the molten adhesive to flow into and upward in a gap located in the aperture between the post and the first conductive layer;   applying heat to solidify the molten adhesive, thereby mechanically attaching the post and the base to the first conductive layer; then   etching the post, thereby forming a first cavity in the adhesive that is located above and extends to the post and faces in the upward direction;   depositing a second conductive layer on the post and the adhesive in the first cavity, thereby forming a second cavity that extends into the first cavity, is located above and spaced from the post, is spaced from the adhesive and faces in the upward direction; then   providing a conductive trace that includes a pad, a terminal and selected portions of the conductive layers;   providing a heat spreader that includes the post, the base and a flange, wherein the flange includes a selected portion of the second conductive layer that defines the second cavity; then   mounting a semiconductor device on the flange, wherein the semiconductor device overlaps the post and extends into the second cavity;   electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and   thermally connecting the semiconductor device to the flange, thereby thermally connecting the semiconductor device to the post, thereby thermally connecting the semiconductor device to the base.   
     
     
         47 . The method of  claim 46 , wherein providing the post and the base includes:
 providing a metal plate;   forming an etch mask on the metal plate that selectively exposes the metal plate and defines the post; and   etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess and the base includes an unetched portion of the metal plate below the post and the recess.   
     
     
         48 . The method of  claim 46 , wherein:
 providing the adhesive includes providing a prepreg with uncured epoxy;   flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the first conductive layer; and   solidifying the adhesive includes curing the uncured epoxy.   
     
     
         49 . The method of  claim 46 , wherein flowing the adhesive includes filling the gap with the adhesive. 
     
     
         50 . The method of  claim 46 , wherein mounting the first conductive layer includes mounting the first conductive layer alone on the adhesive. 
     
     
         51 . The method of  claim 46 , wherein mounting the first conductive layer includes mounting the first conductive layer and a dielectric layer on the adhesive. 
     
     
         52 . The method of  claim 46 , wherein providing the pad and the flange includes removing selected portions of the conductive layers using an etch mask that defines the pad and the flange. 
     
     
         53 . The method of  claim 46 , wherein providing the pad and the flange includes:
 grinding the post, the adhesive and the first conductive layer such that the post, the adhesive and the first conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction; then   depositing the second conductive layer; and   removing selected portions of the conductive layers using an etch mask that defines the pad and the flange.   
     
     
         54 . The method of  claim 46 , wherein providing the terminal includes removing selected portions of the base. 
     
     
         55 . The method of  claim 46 , wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the flange, electrically connecting the semiconductor device includes providing a wire bond between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the die attach between the semiconductor device and the flange. 
     
     
         56 . A method of making a semiconductor chip assembly, comprising:
 providing a post, a base, an adhesive and a substrate, wherein
 the substrate includes a first conductive layer and a dielectric layer, 
 the post is adjacent to the base, extends above the base in an upward direction, extends through an opening in the adhesive and extends into an aperture in the substrate, 
 the base extends below the post in a downward direction opposite the upward direction and extends laterally from the post in lateral directions orthogonal to the upward and downward directions, 
 the adhesive is mounted on and extends above the base, is sandwiched between the base and the substrate and is non-solidified, 
 the substrate is mounted on and extends above the adhesive, and the first conductive layer extends above the dielectric layer, and 
 a gap is located in the aperture between the post and the substrate; then 
   flowing the adhesive into and upward in the gap;   solidifying the adhesive; then   etching the post, thereby forming a first cavity in the adhesive that is located above and extends to the post and faces in the upward direction;   depositing a second conductive layer on the post and the adhesive in the first cavity and on the adhesive and the first conductive layer outside the first cavity, thereby forming a second cavity that extends into the first cavity, is located above and spaced from the post, is spaced from the adhesive and faces in the upward direction; then   providing a conductive trace that includes a pad, a terminal and selected portions of the conductive layers;   providing a heat spreader that includes the post, the base and a flange, wherein the flange includes a selected portion of the first conductive layer and a selected portion of the second conductive layer that defines the second cavity and overlaps the adhesive, the dielectric layer and the first conductive layer outside the first cavity; then   mounting a semiconductor device on the flange, wherein the semiconductor device overlaps the post and extends into the second cavity;   electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and   thermally connecting the semiconductor device to the flange, thereby thermally connecting the semiconductor device to the post, thereby thermally connecting the semiconductor device to the base.   
     
     
         57 . The method of  claim 56 , wherein providing the post and the base includes:
 providing a metal plate;   forming an etch mask on the metal plate that selectively exposes the metal plate and defines the post; and   etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess and the base includes an unetched portion of the metal plate below the post and the recess.   
     
     
         58 . The method of  claim 56 , wherein:
 providing the adhesive includes providing a prepreg with uncured epoxy;   flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the substrate; and   solidifying the adhesive includes curing the uncured epoxy.   
     
     
         59 . The method of  claim 56 , wherein flowing the adhesive includes filling the gap with the adhesive. 
     
     
         60 . The method of  claim 56 , wherein depositing the second conductive layer includes electroplating the second conductive layer. 
     
     
         61 . The method of  claim 56 , wherein depositing the second conductive layer includes the second conductive layer covering the post, the adhesive and the substrate in the upward direction. 
     
     
         62 . The method of  claim 56 , wherein providing the pad and the flange includes removing selected portions of the conductive layers using an etch mask that defines the pad and the flange. 
     
     
         63 . The method of  claim 56 , wherein providing the pad and the flange includes:
 grinding the post, the adhesive and the first conductive layer such that the post, the adhesive and the first conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction; then   depositing the second conductive layer on the post and the adhesive in the first cavity and on the adhesive and the first conductive layer outside the first cavity; and   removing selected portions of the conductive layers using an etch mask that defines the pad and the flange.   
     
     
         64 . The method of  claim 56 , wherein providing the terminal includes removing selected portions of the base after solidifying the adhesive. 
     
     
         65 . The method of  claim 56 , wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the flange, electrically connecting the semiconductor device includes providing a wire bond between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the die attach between the semiconductor device and the flange. 
     
     
         66 . A method of making a semiconductor chip assembly, comprising:
 providing a post and a base, wherein the post is adjacent to and integral with the base and extends above the base in an upward direction, and the base extends below the post in a downward direction opposite the upward direction and extends laterally from the post in lateral directions orthogonal to the upward and downward directions;   providing an adhesive, wherein an opening extends through the adhesive;   providing a substrate that includes a first conductive layer and a dielectric layer, wherein an aperture extends through the substrate;   mounting the adhesive on the base, including inserting the post through the opening, wherein the adhesive extends above the base and the post extends through the opening;   mounting the substrate on the adhesive, including inserting the post into the aperture, wherein the substrate extends above the adhesive, the first conductive layer extends above the dielectric layer, the post extends through the opening into the aperture, the adhesive is sandwiched between the base and the substrate and is non-solidified, and a gap is located in the aperture between the post and the substrate; then   applying heat to melt the adhesive;   moving the base and the substrate towards one another, thereby moving the post upward in the aperture and applying pressure to the molten adhesive between the base and the substrate, wherein the pressure forces the molten adhesive to flow into and upward in the gap and the post and the molten adhesive extend above the dielectric layer;   applying heat to solidify the molten adhesive, thereby mechanically attaching the post and the base to the substrate; then   etching the post, thereby forming a first cavity in the adhesive that is located above and extends to the post and faces in the upward direction;   depositing a second conductive layer on the post and the adhesive in the first cavity and on the adhesive and the first conductive layer outside the first cavity, thereby forming a second cavity that extends into the first cavity, is located above and spaced from the post, is spaced from the adhesive and faces in the upward direction; then   providing a conductive trace that includes a pad, a terminal and selected portions of the conductive layers;   providing a heat spreader that includes the post, the base and a flange, wherein the flange includes a selected portion of the first conductive layer and a selected portion of the second conductive layer that defines the second cavity and overlaps the adhesive, the dielectric layer and the first conductive layer outside the first cavity; then   mounting a semiconductor device on the flange, wherein the semiconductor device overlaps the post and extends into the second cavity;   electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and   thermally connecting the semiconductor device to the flange, thereby thermally connecting the semiconductor device to the post, thereby thermally connecting the semiconductor device to the base.   
     
     
         67 . The method of  claim 66 , wherein providing the post and the base includes:
 providing a metal plate;   forming an etch mask on the metal plate that selectively exposes the metal plate and defines the post; and   etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess and the base includes an unetched portion of the metal plate below the post and the recess.   
     
     
         68 . The method of  claim 66 , wherein:
 providing the adhesive includes providing a prepreg with uncured epoxy;   flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the substrate; and   solidifying the adhesive includes curing the uncured epoxy.   
     
     
         69 . The method of  claim 66 , wherein providing the pad and the flange includes:
 grinding the post, the adhesive and the first conductive layer such that the post, the adhesive and the first conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction; then   depositing the second conductive layer; and   removing selected portions of the conductive layers using an etch mask that defines the pad and the flange.   
     
     
         70 . The method of  claim 66 , wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the flange, electrically connecting the semiconductor device includes providing a wire bond between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the die attach between the semiconductor device and the flange.