SSI PoP
10622291 ยท 2020-04-14
Assignee
Inventors
Cpc classification
H01L25/18
ELECTRICITY
H01L2221/68359
ELECTRICITY
H01L2224/73204
ELECTRICITY
H01L23/3142
ELECTRICITY
H01L21/4853
ELECTRICITY
H01L21/78
ELECTRICITY
H01L2224/1329
ELECTRICITY
H01L2224/8188
ELECTRICITY
H01L2224/131
ELECTRICITY
H01L2224/13294
ELECTRICITY
H01L2224/293
ELECTRICITY
H01L2224/73204
ELECTRICITY
H01L24/97
ELECTRICITY
H01L2224/133
ELECTRICITY
H01L23/498
ELECTRICITY
H01L2924/19102
ELECTRICITY
H01L2224/32225
ELECTRICITY
H01L21/486
ELECTRICITY
H01L2225/06517
ELECTRICITY
H01L21/563
ELECTRICITY
H01L23/49816
ELECTRICITY
H01L2224/131
ELECTRICITY
H01L2224/32225
ELECTRICITY
H01L2224/2929
ELECTRICITY
H01L2224/16113
ELECTRICITY
H01L25/16
ELECTRICITY
H01L2924/00
ELECTRICITY
H01L2224/2929
ELECTRICITY
H01L2224/16227
ELECTRICITY
H01L2924/00
ELECTRICITY
H01L2224/13294
ELECTRICITY
H01L23/49827
ELECTRICITY
H01L2224/8188
ELECTRICITY
H01L25/0652
ELECTRICITY
H01L2225/06548
ELECTRICITY
H01L2224/293
ELECTRICITY
H01L2924/00014
ELECTRICITY
H01L2221/68381
ELECTRICITY
H01L2224/97
ELECTRICITY
H01L25/50
ELECTRICITY
H01L2224/16225
ELECTRICITY
H01L2225/0652
ELECTRICITY
H01L2924/00014
ELECTRICITY
H01L2224/133
ELECTRICITY
H01L2225/06572
ELECTRICITY
H01L2224/16225
ELECTRICITY
H01L2225/1058
ELECTRICITY
H01L2224/1329
ELECTRICITY
H01L2221/68345
ELECTRICITY
H01L23/49811
ELECTRICITY
H01L2224/97
ELECTRICITY
H01L23/04
ELECTRICITY
H01L2224/81192
ELECTRICITY
H01L21/4846
ELECTRICITY
International classification
H01L25/065
ELECTRICITY
H01L23/498
ELECTRICITY
H01L21/48
ELECTRICITY
H01L23/28
ELECTRICITY
H01L23/48
ELECTRICITY
H01L21/78
ELECTRICITY
H01L23/52
ELECTRICITY
H01L23/04
ELECTRICITY
H01L25/18
ELECTRICITY
Abstract
An assembly can include a first microelectronic package and a circuit structure comprising a plurality of dielectric layers and electrically conductive features thereon. The first package can include a substrate having a plurality of first contacts at a first or second surface thereof and a plurality of second contacts at the first surface thereof, and a first microelectronic element having a plurality of element contacts at a front surface thereof. The first contacts can be electrically coupled with the element contacts of the first microelectronic element. The electrically conductive features of the first circuit structure can include a plurality of bumps at the first surface of the circuit structure facing the second contacts of the substrate and joined thereto, a plurality of circuit structure contacts at a second surface of the circuit structure, and a plurality of traces coupling at least some of the bumps with the circuit structure contacts.
Claims
1. A method of making an assembly, comprising: forming a circuit structure mechanically coupled to a surface of a carrier, the forming including: forming a first dielectric layer mechanically coupled to the carrier and forming a plurality of circuit structure contacts and a plurality of conductive traces supported by the first dielectric layer, at least some of the plurality of conductive traces having maximum widths less than two microns, forming a second dielectric layer mechanically coupled with the first dielectric layer, wherein the carrier provides support during formation of the first and second dielectric layers of the circuit structure thereon, and forming bumps at a surface of the second dielectric layer opposite from a surface of the first dielectric layer that faces the carrier, the bumps being electrically coupled with the plurality of circuit structure contacts through the plurality of conductive traces; joining the bumps of the circuit structure with a plurality of second contacts at a first surface of a substrate having a first microelectronic element mounted to first contacts of the substrate, the second contacts facing the bumps; providing an encapsulant extending between the circuit structure and the substrate, wherein a portion of the encapsulant extends between a second surface of the circuit structure and an edge surface of the substrate; and separating the circuit structure from the carrier, wherein the plurality of circuit structure contacts are configured for connection with corresponding contacts of a component external to the assembly, and wherein the joining the bumps is performed to unite the circuit structure with the substrate, the method further comprising providing an underfill surrounding and mechanically reinforcing individual bumps of the assembly and contacting the first surface of the substrate and a surface of the circuit structure facing the substrate, the underfill being separate from the encapsulant, the underfill having a composition different from a composition of the substrate, and different from a composition of the circuit structure.
2. The method as claimed in claim 1, wherein the component external to the assembly is a microelectronic package having a second microelectronic element therein, and the corresponding contacts of the component are terminals at a surface of the microelectronic package electrically coupled with element contacts of the second microelectronic element, the method further comprising joining at least some of the plurality of circuit structure contacts with the terminals of the microelectronic package.
3. The method as claimed in claim 1, wherein the component external to the assembly is a second microelectronic element, the method further comprising joining at least some of the plurality of circuit structure contacts with element contacts of the second microelectronic element.
4. The method as claimed in claim 1, wherein the plurality of conductive traces are first traces, and the maximum widths of the first traces are defined by no first traces having greater widths than two microns, and the forming of the circuit structure includes forming second traces after forming the first traces, the second traces electrically coupled with the first traces, and at least some of the second traces having maximum widths larger than the maximum widths of the first traces.
5. The method as claimed in claim 1, wherein the substrate is a first substrate, the method further comprising: joining the bumps of the circuit structure with a plurality of second contacts at a first surface of a second substrate having a second microelectronic element mounted to first contacts of the second substrate, the second contacts facing the bumps; and after separating the circuit structure from the carrier, singulating the assembly into a first assembly including the first substrate and a second assembly including the second substrate.
6. A method of making an assembly, comprising: forming a circuit structure mechanically coupled to a surface of a carrier, the forming including: forming a first dielectric layer mechanically coupled to the carrier and forming a plurality of circuit structure contacts and a plurality of conductive traces supported by the first dielectric layer, at least some of the plurality of conductive traces having maximum widths less than two microns, forming a second dielectric layer mechanically coupled with the first dielectric layer, and forming bumps at a surface of the second dielectric layer opposite from a surface of the first dielectric layer that faces the carrier, the bumps being electrically coupled with the plurality of circuit structure contacts through the plurality of conductive traces; joining the bumps of the circuit structure with a plurality of second contacts at a first surface of a substrate having a first microelectronic element mounted to first contacts of the substrate, the second contacts facing the bumps; providing an encapsulant extending between the circuit structure and the substrate, wherein a portion of the encapsulant extends between a second surface of the circuit structure and an edge surface of the substrate; and separating the circuit structure from the carrier, wherein the plurality of circuit structure contacts are configured for connection with corresponding contacts of a component external to the assembly, further comprising connecting at least some of the circuit structure contacts with the corresponding contacts of the component external to the assembly, wherein the carrier provides support during formation of the first and second dielectric layers of the circuit structure thereon, and the circuit structure is separated from the carrier prior to the connecting, wherein the joining the bumps is performed to unite the circuit structure with the substrate, the method further comprising providing an underfill surrounding and mechanically reinforcing individual bumps of the assembly and contacting the first surface of the substrate and a surface of the circuit structure facing the substrate, the underfill being separate from the encapsulant, the underfill having a composition different from a composition of the substrate, and different from a composition of the circuit structure.
7. The method as claimed in claim 6, wherein a release layer maintains the circuit structure atop the carrier during formation of the first and second dielectric layers, and the circuit structure is separated from the carrier by releasing the release layer.
8. The method as claimed in claim 6, wherein the circuit structure is separated from the carrier by abrading the carrier.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
DETAILED DESCRIPTION
(6) As used in this disclosure with reference to a dielectric element or other component, e.g., circuit structure, interposer, microelectronic element, circuit panel, substrate, etc., a statement that an electrically conductive element is at a surface of a component indicates that, when the component is not assembled with any other element, the electrically conductive element is available for contact with a theoretical point moving in a direction perpendicular to the surface of the substrate toward the surface of the component from outside the component. Thus, a terminal or other conductive element that is at a surface of a component may project from such surface; may be flush with such surface; or may be recessed relative to such surface in a hole or depression in the component.
(7) A statement that one feature is disposed at a greater height above a surface than another feature means that the one feature is at a greater distance in the same orthogonal direction away from the surface than the other feature. Conversely, a statement that one feature is disposed at a lesser height above a surface than another feature means that the one feature is at a smaller distance in the same orthogonal direction away from the surface than the other feature. As used herein, a statement that one surface or element is located at a constant height above or below another surface or element means constant within manufacturing tolerances, e.g., 10% over the area of a completed single interconnection element.
(8) As illustrated in
(9) The assembly 100 can be joined to and electrically interconnected with one or more second microelectronic elements 160 that can be mounted to the second surface 114 of the circuit structure 110. In one example, the first microelectronic element 140 can have a processor function, and the one or more second microelectronic elements 160 can have a memory function. For example, the first microelectronic element 140 can be an application processor such as a baseband processor. In one example, the second microelectronic elements 160 can include high-bandwidth memory chips. In a particular embodiment, the second microelectronic elements 160 can each embody a greater number of active devices to provide memory storage array function than any other function.
(10) The assembly 100 can be joined to and electrically interconnected with a circuit panel 170, the terminals 122 of the assembly being electrically coupled to panel contacts 172 at a major surface 174 of the circuit panel by conductive bond material 176, for example, with the major surface of the circuit panel confronting the second surface of the substrate 130.
(11) In
(12) The circuit structure 110 can comprise or can be made of a plurality of thin dielectric layers 116 stacked one atop another, and electrically conductive features thereon such as bumps 180 at the first surface 112, circuit structure contacts 182 at the second surface 114, and conductive traces 184 electrically coupling the bumps with the circuit structure contacts. In one example, the circuit structure 110 can have a maximum thickness T1 of less than 50 microns in a direction normal to the first surface 112 of the circuit structure. In particular embodiment, the circuit structure 110 can have a maximum thickness T1 of less than 10 microns in a direction normal to the first surface 112 of the circuit structure.
(13) With the circuit structure 110 comprising or being made of dielectric layers rather than semiconductor material, and omitting semiconductor material as a primary material supporting the electrically conductive features of the circuit structure, advantages for cost of the circuit structure, simplified fabrication, and other advantages can be obtained as described below.
(14) The dielectric material of the dielectric layers 116 can be a material that can be deposited and patterned to form structures that support metallization thereon at a pitch of less than 5 microns, less than 2 microns, less than 1 micron, or at least as low as 0.2 microns. In one embodiment, each dielectric layer 116 can be planarized before depositing the next dielectric layer.
(15) The dielectric layers 116 may be made of silicon dioxide or polyamide, for example. In particular examples, the dielectric material can be a photosensitive polymer, e.g., benzocyclobutene (BCB) based material, or other photosensitive material. In particular examples, the dielectric material can be deposited by chemical vapor deposition (CVD), spray coating, spin coating, roller coating, dipping, or the like. In particular examples, a self-planarizing dielectric material can be deposited to form one or more of the dielectric layers, such material having a tendency to form a flattened or flat upper surface as compared to topography that may be present in features underlying the upper surface.
(16) As further seen in
(17) The electrically conductive features including the bumps 180, the circuit structure contacts 182, and the traces 184 can be made of an electrically conductive material, for example, a metal such as copper, gold, or the like. In one example, the bumps 180 can comprise an electrically conductive bond material such as solder, tin, indium, gold, a eutectic composition or combination thereof, another joining material such as a conductive paste or a conductive adhesive, and/or an electrically conductive composition that includes a metal component such as metal particles or flakes and a polymeric component. Such bumps can be deposited onto portions of the traces 184.
(18) In a particular embodiment, the conductive bond material of the bumps 180 can include an electrically conductive matrix material such as described in U.S. patent application Ser. Nos. 13/155,719 and 13/158,797, the disclosures of which are hereby incorporated herein by reference. In a particular embodiment, the conductive bond material of the bumps 180 can have a similar structure or be formed in a manner as described therein. In some examples, suitable materials for the conductive bond material of the bumps 180 can include polymers filled with conductive material in particle form such as metal-filled polymers, including, for example, metal-filled epoxy, metal-filled thermosetting polymers, metal-filled thermoplastic polymers, or electrically conductive inks.
(19) Alternatively, the bumps 180 can comprise posts or pins, or stud bumps or bond via interconnects each formed of extruded wire, such bumps projecting to heights thereof from the first surface 112. The bumps 180 can be joined with second contacts 138 at the first surface 132 of the substrate 130 at such heights with an electrically conductive bond material such as those described above, for example.
(20) As shown in
(21) The traces 184 on the circuit structure 110 may have their smallest pitch and their smallest line and space dimensions at positions that are closer to the second surface 114 of the circuit structure than the first surface 112. Thus, traces 184 of the circuit structure 110 that are disposed closer to the first surface 112 may have maximum widths greater than maximum widths of the conductive traces that are disposed closer to the second surface 114. At least some of the traces 184 can have maximum widths less than five microns, less than 2 microns, less than 1 micron, or at least as low as 0.2 microns.
(22) Alternatively, the traces 184 on the circuit structure 110 may have their smallest pitch and their smallest line and space dimensions at positions that are closer to the first surface 112 of the circuit structure than the second surface 114. In one example, the traces 184 on the circuit structure 110 may have approximately equal pitch and their smallest line and space dimensions at positions close to both of the first and second surfaces 112, 114.
(23) The first microelectronic package 120 can have a substrate 130 defining first and second opposite surfaces 132, 134. The substrate 130 in some cases can have a thickness T2 of 1 to 2 millimeters in a direction normal to the front surface 132. The substrate 130 can have a single-metal layer or multiple-metal layer structure. In one embodiment, the substrate 130 can have layers made of an organic material or a polymer-based material, for example.
(24) In a particular example, the supporting dielectric structure can be reinforced by glass or semiconductor particles, rods or other such structure embedded within the dielectric material, which can be of or include any or all of epoxies, thermosetting plastics or thermoplastics, polyimide, polycarbonate, polytetra-fluoroethylene (PTFE), polymethyl methacrylate (PMMA), low-K dielectric materials, e.g., porous dielectric materials, low glasses, ceramics, or other materials. In particular examples, the substrate 130 can be of FR-4 or BT resin construction.
(25) The substrate 130 can have electrically conductive features thereon. As shown in
(26) The first microelectronic package 120 can have one or more first microelectronic elements 140 mounted to the substrate 130. As shown in
(27) Although the first microelectronic package 120 is shown in
(28) Although the first microelectronic element 140 is shown in
(29) In a particular embodiment, a rear surface 148 of one or more first microelectronic elements 140 can be mounted to the first surface 132 of the substrate 130 by an adhesive, for example, and the front surface 142 bearing the element contacts 144 can be electrically connected to the bumps 180 at the first surface 112 of the circuit structure 110. In other examples, the first microelectronic package 120 can include a plurality of first microelectronic elements 140 mounted to and electrically connected with conductive elements of the substrate 130.
(30) In a particular example, the element contacts 144 of a first one of the first microelectronic elements 140 can be electrically coupled with a first subset of the first contacts 136 of the substrate 130, and a second one of the first microelectronic elements can be electrically coupled with a second subset of the first contacts of the substrate.
(31) In one example (not shown), one or more of the microelectronic elements 160 having contact-bearing faces at a greater height from the second surface 114 than one or more others of the microelectronic elements, can partially overlap the one or more other microelectronic elements. For example, the microelectronic elements can be arranged and interconnected with the circuit structure in a manner such as seen in commonly-owned U.S. Pat. No. 8,952,516 to Zohni et al., the disclosure of which is incorporated by reference herein.
(32) The first microelectronic package 120 can have an encapsulant 150 at least partially covering the first microelectronic element and the first surface 132 of the substrate 130. The encapsulant 150 can contact peripheral edge surfaces 139 of the substrate 130. The encapsulant may also flow between the facing first surfaces 112 and 132 of the circuit structure 110 and the substrate 130, reinforcing the connections therebetween through the bumps 180.
(33) Alternatively, a separate encapsulant can surround individual bumps 180 and can fill spaces between the first surface 112 of the circuit structure and the first surface 132 of the substrate 130. Such encapsulant can be an underfill material for mechanically reinforcing connections between the circuit structure and the dielectric element through the bumps 180.
(34) The material of the encapsulant 150 most typically has a composition different from the composition of the dielectric layers of the circuit structure and the dielectric element. In particular embodiments, the encapsulant material is an overmold or potting compound. Such compound can provide stiffness to the assembly to withstand internal differential thermal expansion within the assembly 100. The compound may in some cases provide protection from shorting and moisture and/or water resistance. As seen in
(35) The assembly 100 can be joined to one or more second microelectronic elements 160 that can be mounted to the second surface 114 of the circuit structure 110. As seen in
(36) However, in another example (not shown), one or more of the microelectronic elements 160 having contact-bearing faces at a greater height from the second surface 114 than one or more others of the microelectronic elements, can partially overlap the one or more other microelectronic elements. For example, the microelectronic elements can be arranged and interconnected with the circuit structure in a manner such as seen in commonly-owned U.S. Pat. No. 8,952,516 to Zohni et al., the disclosure of which is incorporated by reference herein.
(37) In some examples, one or more electronic components, which may be passive components such as capacitors, resistors or inductors, or active components such as voltage regulators or buffer elements, can be provided in the assembly 100. For example, one or more of such passive and/or active components can be mounted to the first surface 112 or the second surface 114 of the circuit structure 100, and/or can be disposed underlying the first surface or the second surface of the circuit structure. Such components can be mounted to the first surface 132 and/or the second surface 134 of the substrate 130, and/or can be embedded in an encapsulant 150 that occupies a volume of the assembly 100 below the first surface 112 of the circuit structure 110.
(38) A method of fabrication will now be described in accordance with
(39) The carrier 190 typically is a flat plate-like element of ceramic, glass, or semiconductor composition, or in some cases, an overmold material. The carrier 190 may have a coefficient of thermal expansion of less than 12 parts per million per degree Celsius (ppm/ C.) in a horizontal plane of the carrier parallel to the surface 192.
(40) The process can be performed so as to form a plurality of dielectric layers 116 and electrically conductive features such as described above with reference to
(41) The first one of the dielectric layers 116 to be formed can include the substrate contacts 182 at the second surface 114 of the circuit structure 110. The last one of the dielectric layers 116 to be formed can include conductive elements 186 at the first surface 112 of the circuit structure 110. The conductive elements 186 can be electrically coupled to the substrate contacts 182 by the conductive traces 184. The conductive elements 186 can be configured to be joined with the bumps 180.
(42) Next, as shown in
(43) In one example, the bumps 180 can be formed on only the first surface 112 of the circuit structure 110 (e.g., the bumps 180a), or only the first surface 132 of the substrate 130 (e.g., the bumps 180b). In another example, masses of bond material can be formed on one of the first surfaces 112, 132 (e.g., the bumps 180c), while conductive elements such as cylindrical or frusto-conical posts or pins, stud bumps, bumps of extruded wire (e.g., the bumps 180 of the assembly 100 shown in
(44) Then, as can be seen in
(45) The encapsulant 150 can then be introduced into spaces below the first surface 112 of the circuit structure 110, the encapsulant filling spaces between adjacent edge surfaces 139 of the substrates 130. Either a separate underfill, or optionally, the same encapsulant 150, can be applied to the space surrounding the bumps 180 between the circuit structure and the substrates.
(46) Referring to
(47) In time, as shown in
(48) Referring again to
(49) An alternative method of forming the bumps 162 at a dielectric layer deposited onto the surface 192 of the carrier 190, before forming the circuit structure 110, is shown and described in the co-owned and co-pending application Reversed Build-Up Substrate for 2.5D, filed on even date herewith, the disclosure of which is hereby incorporated by reference herein.
(50)
(51) As shown in
(52) In the example shown, the second microelectronic elements 260 are flip-chip mounted to the substrate 230 in a partially-overlapping configuration. In other examples, the one or more second microelectronic elements 260 can be attached to the substrate 230 and arranged relative to the substrate 230 in various configurations including those described above with reference to the first microelectronic elements 140 and the second microelectronic elements 160 (e.g., face-down flip-chip mounted, face-down wire-bonded, face-up wire-bonded, face-down partially-overlapping, etc.).
(53) In one example, the first microelectronic element 140 can have a processor function, and the one or more second microelectronic elements 260 can have a memory function. For example, the first microelectronic element 140 can be an application processor such as a baseband processor. In one example, the second microelectronic package 200 can be a memory package, and the second microelectronic elements 260 can include high-bandwidth memory chips. In a particular embodiment, the second microelectronic elements 260 can each embody a greater number of active devices to provide memory storage array function than any other function.
(54) The PoP assembly 300 can be joined to and electrically interconnected with a circuit panel 170, the terminals 122 of the assembly 100 being electrically coupled to panel contacts 172 at a major surface 174 of the circuit panel by conductive bond material 176, for example, with the major surface of the circuit panel confronting the second surface 134 of the substrate 130.
(55) The interconnection elements described above with reference to
(56) In the exemplary system 400 shown, the system can include a circuit panel, motherboard, or riser panel 402 such as a flexible printed circuit board, and the circuit panel can include numerous conductors 404, of which only one is depicted in
(57) In the example depicted in
(58) Modules or components 406 and components 408 and 411 can be mounted in a common housing 401, schematically depicted in broken lines, and can be electrically interconnected with one another as necessary to form the desired circuit. The housing 401 is depicted as a portable housing of the type usable, for example, in a cellular telephone or personal digital assistant, and screen 410 can be exposed at the surface of the housing. In embodiments where a structure 406 includes a light-sensitive element such as an imaging chip, a lens 411 or other optical device also can be provided for routing light to the structure. Again, the simplified system shown in
(59) Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
(60) It will be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims. It will also be appreciated that the features described in connection with individual embodiments may be shared with others of the described embodiments.