JP5602685B2 - Multi-package module and method for forming the same - Google Patents

Description

  The present invention relates to semiconductor packaging.

  Portable electronic products, such as cell phones, portable computer equipment, and various products, require higher semiconductor capabilities and capabilities at the lowest cost, with limited top space and minimum thickness and weight. This leads to increased integration in individual semiconductor chips in the industry.

  Recently, in the industry, integration on the “z-axis”, that is, realization of stacking of chips has started, and even one in which five chips are stacked in one package is used. As a result, a dense chip structure having a one-chip package upper surface space in the range of 5 × 5 mm to 40 × 40 mm is provided, and the thickness is gradually reduced from 2.3 mm to 0.5 mm. The cost of stacked die packages only increases incrementally over the cost of a single die package, and the assembly is a competitive final compared to die package packaging in an individual package. High enough to ensure a reasonable cost.

  A fundamental useful limitation on the number of chips stacked in a stacked die package is the low final yield of the stacked die package. Depending on the package die, the size drawback may be unavoidable, so the final package test yield is an inevitable die test yield product, each test yield always being less than 100%. This is particularly problematic even if only two dies are stacked in the package. Some of them are low due to design complexity or technology.

  Another limitation is low power consumption in the package. Heat is transferred from one die to the other and is less important than solder balls through the motherboard.

  A further limitation is electromagnetic interference between stacked dies, in particular between RF and digital dies, since they are not electrically shielded at each other.

  Another approach to integration on the “z-axis” is to stack dice packages to form a multi-package module. Stacked packages have a number of advantages over stacked die packages.

  For example, each package with a die can be electrically tested and rejected before the package is stacked unless satisfactory performance is achieved. As a result, the final stacked multi-package module product is maximized.

  Inserting a heat spreader similar to that at the top of the module between the stacked packages provides a more effective cooling method for the stacked packages.

  Package stacking allows electromagnetic shielding of the RF dice and avoids interference with other dice in the module.

  Each die or more than one die can be packaged within each package in the stack using the most effective first-class interconnect technology for chip type and alignment, such as wire bonding and flip chip It is. This maximizes performance and minimizes cost.

  Z-axis interconnection between packages in stacked multi-package modules is a decisive technique in terms of manufacturing capability, design flexibility and cost. The proposed z-interconnect has a flexible substrate with the peripheral solder ball connections and the top of the bottom package folded. The use of peripheral solder balls in z-interconnects in stacked multi-package modules limits the number of connections that determine and limit the degree of design freedom, resulting in a thicker and higher cost package. Although the use of a flexible folding substrate is provided on the principle of freedom of design, no manufacturing equipment for the folding process has been established. Furthermore, the flexible folded substrate requires two metal layer flex substrates, which are very expensive. Furthermore, the proximity of the folded flexible board is constrained by low pin count applications because the path design of the circuit configuration of the two metal layer boards is limited.

Various z-axis interconnect structures are described in more detail with reference to FIGS. 1-4.
FIG. 1 is a cross-sectional view illustrating the structure of a standard ball grid array (“BGA”) package that can be used as a bottom package of stacked multi-package modules (“MPM”) and is well established in industry. is there. A BGA is shown generally as 10 and has a die 14 mounted on a substrate 12 having at least one metal layer. Any of a variety of substrate types may be used, for example, laminating 1-2 metal layers, substrate structure having 4-8 metal layers, flexible polyimide tape or ceramic multi-layer having 1-2 metal layers A substrate is included. The substrate 12 illustrated by the example of FIG. 1 has two metal layers 121, 123 that are each patterned to provide an appropriate circuit configuration and are connected to each other via a bias 122. The die is attached to the surface of the substrate at a predetermined location using an adhesive generally referred to as a die bonding epoxy indicated by 13 in FIG. In the configuration of FIG. 1, even if the die bonding surface does not require a specific orientation when in use, the surface on the substrate to which the die is attached is referred to as the “upper” surface, This metal layer is referred to as the “upper” metal layer.

  In the BGA of FIG. 1, the dice are wire bonded to the wire bond surface on the upper metal layer of the substrate to establish an electrical connection. The die 14 and the wire bond 16 are encapsulated by a mold compound 17. This will facilitate ease of handling by protecting against ambient and mechanical stress. Moreover, the surface for the marking for identification will be provided. Solder balls 18 reflow over the bonding pads on the lower metal layer of the substrate and are interconnected to a final product motherboard (not shown) such as a computer. The solder masks 125 and 127 are patterned on the metal layers 121 and 123 so that the underlying metal is exposed on the bonding surface for electrical connection. For example, for electrical connection of bonding pads and solder balls 18 for the wire bond surface and bonding wire bond 16.

  FIG. 2 is a cross-sectional view illustrating a structure according to an example of two stacked MPMs. Generally as 20, the z-axis interconnection between the stacked packages is formed by solder balls. In this MPM, the first package (referred to as the “bottom” package) is similar to the standard BGA shown in FIG. 1 (and similar reference numbers are similar for the bottom package in FIGS. 1 and 2). Adopted in places showing the characteristics of). The second package (referred to as the “top” package) is stacked on the bottom package and the solder balls in the top package are top package substrates so that they are effective for z-axis interconnections that do not interfere with the encapsulation of the bottom BGA. The structure is the same as that of the bottom package except that it is arranged at the periphery of the bottom package. In particular, the top package of FIG. 2 includes a die 24 mounted on a substrate 22 having at least one metal layer. The top package substrate 22 illustrated by the example of FIG. 2 has two metal layers 221, 223, each patterned to provide an appropriate circuit configuration and connected via a bias 222. The die is attached to a predetermined location on the surface of the substrate (the “upper” surface) using an adhesive commonly referred to as a die bonding epoxy, indicated at 23 in FIG.

  In the top package in the MPM of FIG. 2, as in the bottom package, the dies are wire bonded onto the wire bond surface of the upper metal layer of the substrate to establish an electrical connection. The top package die 24 and wire bond 26 are encapsulated by a top package mold compound 27. Solder balls 28 are reflowed onto bonding pads located at the peripheral edges of the lower metal layer of the top package substrate to form a z-axis interconnect with the bottom package. The solder masks 225 and 227 are patterned on the metal layers 221 and 223 so that the underlying metal is exposed on the bonding surface for electrical connection. For example, for the electrical connection of bonding pads and solder balls 28 for wire bond surfaces and bonding wire bonds 26.

  The z-axis interconnection in the MPM of FIG. 2 is achieved by reflow of solder balls 28 attached to the peripheral bonding pads on the upper metal layer of the bottom BGA. In this configuration, the distance h between the top package and the bottom package must be at least as large as the encapsulated height of the bottom package, and should be approximately 0.3 mm or more, generally 0 The range is between 5 mm and 1.5 mm. Therefore, the solder balls 28 must be sufficiently large in diameter so that they will make good contact with the bottom BGA bonding pads when they reflow. That is, the diameter of the solder ball 28 must be greater than the encapsulated height. A larger ball diameter requires a larger ball pitch. This in turn limits the number of balls that can be mounted in the space where it can be mounted. Furthermore, the placement around the solder balls makes the bottom BGA sufficiently larger than a standard BGA die cap. In a small BGA, the body size of a package commonly referred to as a chip scale package (“CSP”) is 1.7 mm larger than a die. In a standard BGA, the body size is approximately 2 mm larger than the die cap. In this configuration, the top package substrate must have at least two metal layers to facilitate electrical connection.

  FIG. 3 is a cross-sectional view illustrating a structure according to an example of a known two-stack flip-chip MPM, generally indicated at 30. In this configuration, the bottom BGA flip chip package includes a substrate 32 having a patterned metal layer 31. On the metal layer 31, a die 34 is connected by a solder ridge, a gold stud ridge or a flip chip ridge 36 such as an anisotropic conductive film or paste. The flip chip ridge 36 is applied to a patterned array of ridge pads on the active surface of the die. The active surface below the die surface relative to the information surface of the patterned metal layer of the substrate in such an arrangement is referred to as a “down-facing die” flip chip package. The polymer underfill 33 between the die and the substrate protects from the surroundings and adds mechanical integrity of the structure. Such a flip chip package, whose substrate has a metal layer only on the upper surface, is connected to a lower circuit configuration (such as a motherboard, not shown) by solder balls 38 connected to the metal layer through solder bias 35. The

  The top BGA in this configuration is the same as the bottom BGA except that the top BGA has a z-axis interconnected solder ball 338 connected to the metal layer 331 (through the top substrate solder bias 335) only at the periphery of the top substrate. It is the same. Solder balls 338 are reflowed onto the bottom substrate metal layer 31 to form a z-axis interconnect. In particular, a top BGA of this configuration comprises a substrate 332 having a metal layer 331 patterned such that the top BGA is connected to the flip chip ridge 336. Between the top BGA die and the substrate is a polymer underfill 33. The structure as shown in FIG. 3 is more suitable for high electrical performance, but has the same limitations as the configuration of the type shown in FIG. Here, what improved the structure of FIG. 2 is shown. That is, the bottom BGA has no mold part, and a solder ball having a smaller diameter (h) can be used around the top BGA for connection between packages.

  FIG. 4 is a cross-sectional view illustrating an example structure of a known two-fold folded flexible substrate MPM, generally indicated as 40. The bottom package in the configuration of FIG. 4 was connected to the first metal layer of the substrate via a small die beam. It has two metal layer flexible substrates. The second metal layer of the bottom package substrate has solder balls for connection to a lower circuit configuration such as a motherboard (not shown). The substrate is large enough to bend over the top of the package, with the electrical interconnect lines facing upwards (illustrated below) so that it can be connected to the top package by an array of solder balls in the top package. The space around the die and between the die and the folded substrate are encapsulated, protected and aligned.

  As shown in FIG. 4, the two-metal layer bottom package substrate 42 includes a first metal layer 141 and a second metal layer 143, is patterned to have an appropriate circuit configuration, and is connected by a bias 143. The portion of the first metal layer that is beyond the portion of the bottom substrate reveals an array of cantilever beams or tabs 46 arranged on the active surface of the bottom package die 44 to match the array of interconnect pads. (For example, an array of punches is used). On the portion of the substrate 42 referred to as the “die mounting portion”, the surface of the first metal layer 141 faces upward. The dice are aligned down the active surface on the die mounting portion of the substrate, and the cantilevers and matching interconnect pads are connected. In general, the electrical connection is completed, for example, by “thermosonic” processing using a combination of pressure, heat, and ultrasonic energy. The dice 44 is affixed onto the dice mounting portion of the flexible substrate 42 using an adhesive 43 that is generally a dice bonding epoxy. The surface of the second metal layer 143 of the bottom package substrate 42 faces downward with respect to the die attachment portion of the substrate. Solder balls 48 are reflowed onto bonding pads located on the array on the downward facing portion of the second metal layer 143 to interconnect the MPM to the underlying circuit configuration (not shown). The solder mask 147 is patterned on the second metal layer 143 to expose the underlying metal as a bonding surface for electrical connection. As will be described later, the electrical connection includes a bond pad for connection to the lower circuit configuration by the solder ball 48 and a bond pad for connection to the top package by the solder ball 18.

  The other part of the bottom package substrate 42, that is, the part extending adjacent to the die attachment portion is bent on the bottom package die 44. In this bent portion of the flexible substrate 42, the surface of the first metal layer 143 faces upward. In the configuration of FIG. 4, the top package is typically similar to the BGA of FIG. 2, with its dice being wire bonded onto the wire bond surface of the upper metal layer of the substrate to establish an electrical connection. . In particular, the top package dice 14 are mounted on a substrate 12 having two metal layers 121 and 123 that are each patterned (in this example) to provide a suitable circuit configuration and connected to each other by a bias 122. The dies are typically attached to the upper surface of the top package substrate using an adhesive 13, which is typically a die attach epoxy. The die 14 and the wire bond 16 are encapsulated by the mold compound 17 to protect from the surroundings and mechanical stress, facilitate handling and provide a surface for marking for identification. Solder balls 18 are reflowed onto bonding pads 143 on the metal layer on the upward facing side of the bottom package substrate that is folded up to form a z-axis interconnect between the top package and the bottom package.

  The advantage of the structure as shown in FIG. 4 is that the folds over folded provide enough area on the upward surface of the bottom package substrate folded up to accommodate the sufficient array of solder balls in the top package. And to accommodate more complex interconnections between the two packages. Securing the top space of a small package is also an advantage. The fundamental disadvantage of this configuration is the high cost for the substrate and the inability to use folding techniques and equipment.

  The challenge common to all these stacked package configurations is that each package can be pre-tested and the final test yield of the product MPM is higher.

  It is an object of the present invention to provide a multi-package module having stacked packages. According to the present invention, the z-axis interconnection between MPM stacked packages is based on wire bonds. In general, the present invention is characterized by various configurations in various stacked packages and stacking and interconnection methods in various packages by wire bonding based z-axis interconnection. In the multi-package module according to the present invention, the stack of packages can include any of various BGA packages and / or any of various land grid array (LGA) packages. That is, package stacks may include wire bond and / or flip chip packages, may include heat-promoting features enabled by one or more heat spreaders in or on the stack, top or One or more packages having flip chip dies bonded to either the bottom BGA or LGA may be included, and one or more BGAs having more than one die in a stacked or side-by-side package and May include LGA, may include electromagnetic shielding of one or more packages, and z-axis interconnect pads such as laminate, build-up, flexible or ceramic can be bonded to the periphery of the package It may include the certain one of the substrates.

  In one overall aspect, the invention features a multi-package module having stacked lower and upper packages, each package having dies attached to the substrate, the upper and lower substrates. Are interconnected by wire bonding.

  The present invention provides for manufacturing stacked package modules having low height and small top space with superior processability, high design freedom, and low cost. Wirebond z-axis interconnects are well established in the industry and are the least cost interconnect technology and can be applied directly to the stacked multi-package modules of the present invention without major changes. This also provides design flexibility for the relative size of the BGA to the LGA bridged by wire length. By using available technology and equipment, the wire in wire bond is 0.5 mm short and 5 mm long. The z-axis interconnect pad can be realized through either or both BGA and LGA substrate designs. Furthermore, by using wire bonds according to the present invention, z-axis interconnects are formed between pads that are not accurately aligned with each other by employing so-called “discontinuous bonding”, which is currently used in industry. Is done. Wire bonding pitch is currently the finest available technology in the industry, currently 50 microns and is planned to be 25 microns. This allows for more z-axis interconnections. Both workability and design freedom contribute to the cost reduction of MPM.

  The minimum top space for a typical BGA or LGA is 1.7 mm larger than the die size. The addition of the z-axis interconnect bond pad according to the present invention increases the BGA size by a minimum of 0.8 mm. Typical BGA thickness is 1.0 mm and LGA thickness is 0.8 mm. Typical adhesive thickness ranges from 0.025 mm to 0.100 mm. The top space and thickness of the stacked packages MPM according to the present invention are both settled within the acceptable range for most applications.

  Depending on the embodiment, the multi-package module has three or more packages and is secured continuously to form a stack.

  In another aspect, the present invention has stacked first ("bottom") and second ("top") packages, each package attached to the substrate and connected to the substrate by wire bonding. It has a die and is characterized in that the top package substrate and the bottom package substrate are interconnected by wire bonding. In some embodiments, each package is fully encapsulated by the mold material. In other embodiments, at least one package is encapsulated only to a sufficient extent to protect wire bonds between the die and the substrate during subsequent processing and testing. In some embodiments, the second package is an LGA package, and in such embodiments, the LGA package substrate may be a single metal layer substrate.

  In another aspect, the present invention is a multi-package module having stacked first (“bottom”) and second (“top”) packages, wherein the bottom package is a BGA package, each package being And a die attached to the substrate, wherein the top package substrate and the BGA package substrate are interconnected by wire bonding.

  In another aspect, the present invention is a multi-package module having stacked packages, wherein at least one package includes an electrical shielding material. In such a configuration, the electrical shielding material may be additionally configured by a heat spreader. In some embodiments, a package comprising an electrical shield has an RF die that is used to limit electromagnetic interference between the RF die and other dies in a multi-package module. In some embodiments, the bottom package includes an electrical shielding material.

  In another aspect, the present invention is a multi-package module having stacked first (“bottom”) and second (“top”) packages, wherein the bottom package is a flip chip BGA package in an upward die configuration. The top substrate and the bottom package are interconnected by wire bonding. In some embodiments, the top package is a stacked die package, and in some embodiments, the adjacent stacked dies in the stacked die package are separable by a spacer. In some embodiments, the flip chip die on the bottom package includes an electrical shielding material. In some embodiments, the bottom package substrate is provided on a ground plane, which is also configured for heat dissipation and as an electrical shield.

  In another aspect, the present invention is a multi-package module having stacked first (“bottom”) and second (“top”) packages, the bottom package having flip chips in a downward die configuration A chip BGA is characterized in that the top substrate and the bottom package are interconnected by wire bonding. In some embodiments, the flip chip die on the bottom package includes an electrical shielding material.

  In another aspect, the present invention is a multi-package module having first (“bottom”) and second (“top”) packages stacked, each package being attached to a substrate and by wire bonding And a die package connected to the substrate, wherein the top package substrate and the bottom package substrate are interconnected by wire bonding, and at least one of the bottom package and the top package is a package of stacked dies. . In some embodiments, both the top package and the bottom package are stacked dice packages.

  In another overall aspect, the present invention is a method of forming a multi-package module, comprising forming a first (bottom) package having at least one die on a first (bottom) package substrate, A second (top) package having at least one die is disposed on a second (top) package substrate over the package, and a wire bond z-axis mutual between the first and second (top and bottom) substrates A connection is formed. Beneficially, these packages can be tested prior to assembly and only the required performance or so that only the first package and the second package tested as “pass” are suitable for use in the assembled module. Packages that do not meet reliability can be eliminated.

  In one aspect, the present invention is a method of forming a multi-package module having LGA packages stacked on a BGA package, wherein the top and bottom packages are electrically interconnected by wire bonding. According to this aspect, the BGA package is typically provided on an unsingulated strip in a molded BGA package. Preferably, the BGA packages in the strip are tested for performance and reliability, and packages that are found to be “passed” are subjected to subsequent processing. The adhesive is applied to the upper surface of the die on the “passed” BGA package. A land grid array package that is singulated and molded, preferably the LGA package has been tested and found to be "pass", and the "pass" LGA package is the "pass" BGA package Place on the adhesive on the die to cure the adhesive. Optionally and preferably, a plasma clean process may be performed after formation of the MPM die. A further step has the mounting of secondary interconnect solder balls on the underside of the module, which allows the finished module to be singulated, eg sawed or punch singulated, for further use Packaging for.

  In some embodiments, the LGA (top) package has a well-molded, substantially planar upper surface of the LGA package, and in some other embodiments, the wire bonds that are not the entire die surface of the LGA package are molded. The LGA die is realized by applying a mold compound around the die and the periphery of the LGA package substrate.

  In another aspect, the present invention is a method of forming a multi-package module in which LGA packages are stacked on a BGA package, wherein the top and bottom packages are electrically connected by wire bonding, and the bottom package is electromagnetically shielded. It is characterized by being. According to this aspect, a ball grid array package, generally a non-separated BGA package, is applied. A shielding material fixed on a die is applied to the BGA package. Preferably, the strip BGA package is subjected to performance and reliability tests and is deemed “pass” and the package submitted for subsequent processing is employed. The adhesive is applied on the upper surface of the “pass” BGA package shield. Then, a land grid array package molded in pieces is applied. Preferably, the LGA package has been tested and found to be “pass”. The “passed” LGA package is mounted on the adhesive on the shield and allowed to cure. Additionally and more preferably, the plasma clean process is performed after formation of the z-axis interconnect by wire bonding between the stacked top LGA and bottom BGA. Additionally and more preferably, additional plasma clean may be applied after the formation of the MPM mold. As a further step, a secondary interconnect solder ball is attached to the underside of the module. The module, which is tested and completed from the strip, is singulated, for example by saw singulation or punch singulation. And package for further use.

In some embodiments, the method includes providing a heat spreader to the multi-package module. In this aspect of the invention, a heat spreader supported by a “drop-in” mold process is inserted intermediately or a similar process is performed with additional steps.
Insert simply by drop-in-molding a flat heat spreader or applying an adhesive to the top package die upper surface or spacer upper surface on the top package and mounting a flat heat spreader over the adhesive To do.

  In another aspect, the present invention is a method of forming a multi-package module having a top package stacked on a downward die flip chip BGA bottom package, wherein the top and bottom packages are electrically connected by wire bonding. It is characterized by that. According to this aspect, a downward die flip chip BGA bottom package, additionally molded, generally a non-singulated strip of a downward die flip chip ball grid array bottom package is applied. Preferably, the strip BGA package is subjected to performance and reliability tests, and a package that is found to be “passed” is subjected to further processing. The adhesive is applied to the upper surface (back surface) of the “pass” BGA package die. The singulated top package (eg, a land grid array package) is additionally molded, and preferably the LGA package has been tested and found to be “pass”. A “pass” LGA package is placed over the adhesive beyond the shield and the adhesive cures. Additionally or preferably, a plasma clean process is applied after the formation of the z-axis interconnect by wire bonding between the stacked top LGA and bottom BGA packages. Additionally or preferably, additional plasma clean may be applied after the formation of the MPM mold. As a further step, a secondary interconnect solder ball is attached to the underside of the module. The module, which is tested and completed from the strip, is singulated, for example by saw singulation or punch singulation. And package for further use.

  In another aspect, the present invention is a method of forming a multi-package module having a top package stacked on a downward die flip chip BGA bottom package, wherein the top and bottom packages are electrically connected by wire bonding, The bottom package is characterized in that it is electrically shielded. According to this aspect, in an unshielded bottom flip chip bottom package, the same performance as described above is obtained by an additional step of interposing a shielding material on the bottom package flip chip die. The downward die flip chip BGA bottom package is additionally molded, and generally an undivided strip of the downward die flip chip ball grid array bottom package is applied. Preferably, the strip BGA package is subjected to performance and reliability tests, and a package that is found to be “passed” is subjected to further processing. The electrical shield is mounted on a die on a “pass” bottom BGA package. The adhesive is applied to the upper surface (back surface) of the “pass” BGA package die. The singulated top package (eg, a land grid array package) is additionally molded, and preferably the LGA package has been tested and found to be “pass”. A “pass” LGA package is placed over the adhesive beyond the shield and the adhesive cures. Additionally or preferably, a plasma clean process is applied after the formation of the z-axis interconnect by wire bonding between the stacked top LGA and bottom BGA packages. Additionally or preferably, additional plasma clean may be applied after the formation of the MPM mold. As a further step, a secondary interconnect solder ball is attached to the underside of the module. The module, which is tested and completed from the strip, is singulated, for example by saw singulation or punch singulation. And package for further use.

  In another aspect, the present invention is a method of forming a multi-package module having a top package stacked on an upward die flip chip BGA bottom package, wherein the top and bottom packages are electrically interconnected by wire bonding. It is characterized by that. According to this aspect, the upward die flip chip ball grid array package is not normally molded, but is usually applied as an undivided strip of the upward die flip chip ball grid array package. Preferably, the strip BGA package is subjected to performance and reliability tests, and a package that is found to be “passed” is subjected to further processing. The adhesive is applied to the upper surface (back surface) of the “pass” BGA package die. Then, the second package is applied. This is, in some embodiments, a stacked die package that is additionally and generally molded. Preferably, the LGA package has been tested and found to be “pass”. A “pass” LGA package is placed over the adhesive and the adhesive is cured. Additionally or preferably, a plasma clean process is applied after the formation of the z-axis interconnect by wire bonding between the stacked top LGA and bottom BGA packages. Additionally or preferably, additional plasma clean may be applied after the formation of the MPM mold. As a further step, a secondary interconnect solder ball is attached to the underside of the module. The module, which is tested and completed from the strip, is singulated, for example by saw singulation or punch singulation. And package for further use.

  In another aspect, the present invention is a method of forming a multi-package module having a top package stacked on a stacked die bottom package, wherein the top and bottom packages are electrically interconnected by wire bonding. It is characterized by that. According to this aspect, the stacked dice BGA packages are generally applied in a molded form, and the undivided strips of the stacked dice ball grid array packages are generally applied. Preferably, the strip BGA package is subjected to performance and reliability tests, and a package that is found to be “passed” is subjected to further processing. Adhesive is applied to the upper surface of a “pass” stacked die BGA package, typically the upper surface which is the plane of the package die. Then, the molded second package is generally a molded one. In addition, it is a package of stacked dies. Preferably, the second package has been tested and found to be “pass”. A “pass” LGA package is placed over the adhesive and the adhesive is cured. Additionally or preferably, a plasma clean process is applied after the formation of the z-axis interconnect by wire bonding between the stacked top LGA and bottom BGA packages. Additionally or preferably, additional plasma clean may be applied after the formation of the MPM mold. As a further step, a secondary interconnect solder ball is attached to the underside of the module. The module, which is tested and completed from the strip, is singulated, for example by saw singulation or punch singulation. And package for further use.

  In some embodiments of the method, two or more first molded packages are provided in an unsingulated strip, and the assembly of two or more modules is advanced in the strip, and two or more The modules are separated after the assembly is completed.

  In the method of forming a multi-package module according to the present invention, the electrical connection between the stacked packages employs known wire bonding to form a z-axis interconnection between the upper and lower package substrates of the stack. Special advantages lie in the use of established manufacturing equipment, low production costs, design freedom, and thin packaging products. Z-axis interconnect wire bonding is used in various package and module configurations to draw a wire from a ridge formed on a conductive pad on a second package substrate to a conductive pad on the first package substrate or on the first package substrate. This is realized by drawing a wire from the ridge formed on the conductive pad of the conductive pad to the conductive pad on the second package substrate.

  The present invention provides one or more semiconductor assemblies that achieve a maximum final test yield at a minimum cost in a thin, minimum top space package. In addition, the stacked configuration of the present invention allows for high thermal performance, high electrical performance or electrical isolation in the RF configuration of digital equipment. Other stack configurations provide very thin structures used for palm size or consumer equipment. All that the method for the assembly provides can be individually tested on the stacked packages, maximizing the end product of the module.

  Additional process steps will be employed to complete the multi-package module according to the present invention. For example, it is preferable not to attach solder balls to the motherboard until the last step before MPM singulation, for the connection of the bottom layer of the stack. Also, for example, plasma clean may be applied at various points in the process, such as after curing of the adhesive and before encapsulation, and before and / or after z-axis interconnect wire bonding.

  Advantageously, the individual packages are provided as strips having several packages arranged in a row for ease of handling during manufacture, and the multi-package module can be It is separated. In the method according to the present invention, the stacking of the packages is performed by attaching the second package separated on the strip of the first package that has not been separated in the selected type until the module forming process is completed. A wire bonded z-axis interconnect is formed and formed by singulating the module.

  The MPM according to the present invention can be used to construct computers, communication equipment, and consumer or industrial electronic devices.

It is sectional drawing of the conventional ball grid array semiconductor package. 1 is a cross-sectional view of a conventional multi-package module having solder ball z-axis interconnections between stacked ball grid array semiconductor packages. FIG. 1 is a cross-sectional view of a conventional multi-package module having solder ball z-axis interconnections between stacked flip chip semiconductor packages. FIG. 1 is a cross-sectional view of a conventional multi-package module having solder ball z-axis interconnections between a folded flexible substrate and stacked semiconductor packages. FIG. 1 is a cross-sectional view illustrating one embodiment of a multi-package module having wire bond z-axis interconnections between stacked BGA and LGA semiconductor packages according to an aspect of the present invention. 5B is a plan view showing a bottom BGA substrate with z-axis interconnect bond pads in a preferred arrangement for use according to the embodiment of the present invention shown in FIG. 5A. FIG. FIG. 5B is a plan view showing a top LGA substrate with z-axis interconnect bond pads in a preferred arrangement for use according to the embodiment of the present invention shown in FIG. 5A. 1 is a cross-sectional view illustrating one embodiment of a multi-package module having a heat spreader attached to an upper surface of a top package with wire bond z-axis interconnection between stacked BGA and LGA semiconductor packages according to one aspect of the present invention. It is. FIG. 6 is a cross-sectional view illustrating one embodiment of a multi-package module having a wire bond z-axis interconnect between a BGA and LGA semiconductor package and having a heat spreader according to another aspect of the present invention. FIG. 6 is a cross-sectional view illustrating another embodiment of a multi-package module having wire bond z-axis interconnections between stacked BGA and LGA semiconductor packages according to an aspect of the present invention, with the top package molded only at the periphery. 4 illustrates another embodiment of a multi-package module having wire bond z-axis interconnections between stacked BGA and LGA semiconductor packages according to an aspect of the present invention, the top package being molded only at the periphery, and the module having a heat spreader. It is sectional drawing. FIG. 6 is a cross-sectional view illustrating another embodiment of a multi-package module having wire bond z-axis interconnections between stacked BGA and LGA semiconductor packages according to an aspect of the present invention, wherein the top package substrate has one metal layer substrate. It is. FIG. 6 is a cross-sectional view illustrating one embodiment of a multi-package module having wire bond z-axis interconnections between stacked BGA and LGA semiconductor packages according to a further aspect of the present invention and having an electrical shield in the bottom package. Another embodiment of a multi-package module having wire bond z-axis interconnections between stacked BGA and LGA semiconductor packages according to one aspect of the invention, having an electrical shield in the bottom package, and the module having a heat spreader FIG. A heat spreader having wire bond z-axis interconnections between stacked BGA and LGA semiconductor packages according to one aspect of the present invention, having an electrical shield in the bottom package, and a module attached to the upper surface of the top package. It is sectional drawing which shows other embodiment of the multipackage module which has. FIG. 4 is a cross-sectional view of a multi-package module having wire bond z-axis interconnections between stacked flip chip BGA (downward dice) and LGA semiconductor packages according to a further aspect of the present invention. FIG. 6 is a cross-sectional view of a multi-package module having wire bond z-axis interconnections between stacked flip chip BGA (downward dice) and LGA semiconductor packages and having an electrical shield in the bottom package according to a further aspect of the present invention. Multi-package with wirebond z-axis interconnection between stacked flip chip BGA (downward dice) and LGA semiconductor packages according to a further aspect of the present invention, with an electrical shield in the bottom package and the module with a heat spreader It is sectional drawing of a module. In accordance with a further aspect of the present invention, there is a wire bond z-axis interconnect between stacked flip chip BGA (upward dies) and dice LGA semiconductor packages, and the stacked dies adjacent to the second package are separated by a spacer. It is sectional drawing of the multi-package module. The die stacked adjacent to the second package has a different size with wire bond z-axis interconnection between stacked flip chip BGA (upward die) and die LGA semiconductor packages according to a further aspect of the present invention. It is sectional drawing of a multi package module. FIG. 6 is a cross-sectional view of a multi-package module having wire bond z-axis interconnections between stacked flip chip BGA (upward dies) and dice LGA semiconductor packages and having an electrical shield in the bottom package according to a further aspect of the present invention. . An upper surface mounting of a top package with wire bond z-axis interconnection between stacked flip chip BGA (upward dies) and dice LGA semiconductor packages according to a further aspect of the invention, with an electrical shield in the bottom package It is sectional drawing of the multi package module which has the heat spreader made. Another aspect of the present invention has wire bond z-axis interconnection between stacked flip chip BGA (upward die) and dice LGA semiconductor packages according to a further aspect of the present invention, and has an electrical shield in the bottom package. It is sectional drawing of the multi-package module which has the heat spreader which concerns on. FIG. 6 is a cross-sectional view of a multi-package module having wire bond z-axis interconnections between stacked BGA (stacked dice) and LGA (stacked dice) semiconductor packages according to a further aspect of the present invention. FIG. 8 is a flowchart illustrating a process for assembling the multi-package module illustrated in FIG. 5A or FIG. 7. FIG. 6B is a flowchart illustrating a process for assembling the multi-package module illustrated in FIG. 6A. It is a flowchart which shows the process for the assembly of the multi package module illustrated by FIG. 8A. FIG. 8B is a flowchart illustrating a process for assembling the multi-package module illustrated in FIG. 8B. 8D is a flowchart showing a process for assembling the multi-package module illustrated in FIG. 8C. It is a flowchart which shows the process for the assembly of the multi package module illustrated by FIG. 9A. FIG. 9B is a flowchart illustrating a process for assembling the multi-package module illustrated in FIG. 9B. FIG. 11 is a flowchart showing a process for assembling the multi-package module illustrated in FIG. 10A or FIG. 10B. 12 is a flowchart showing a process for assembling the multi-package module exemplified in FIG.

  The invention is explained in more detail by means of reference figures illustrating embodiments of the invention. Each drawing is exaggerated in order to clearly show the features of the present invention and to show the relationship with other features and configurations. Moreover, in each figure, about the same element, a code | symbol is not attached again.

  In FIG. 5A, an embodiment of a multi-package module according to an aspect of the present invention comprising first (“bottom”) and second (“top”) packages stacked is shown generally at 50 in a cross-sectional view. ing. Among them, the stacked packages are interconnected by wire bonds. In the configuration shown in FIG. 5A, the bottom package 400 is a conventional BGA package as shown in FIG. Accordingly, in this form, the bottom package 400 comprises a die 414 mounted on a bottom package substrate 412 having at least one metal layer. Any of a variety of substrate types can be used. For example, a laminate having 2 to 6 metal layers, or a substrate having 4 to 8 metal layers, or a flexible polyimide tape having 1 or 2 metal layers, or a ceramic product layer substrate is also included. The bottom package substrate 412 illustrated in FIG. 5A has two metal layers 421 and 423, each of which is formed to supply a special electrical circuit and connected to each other by a bias 422. ing. The dies are commonly referred to as die bonded epoxies and are bonded to the surface of the substrate using the adhesive shown at 413 in FIG. 5A. In the configuration of FIG. 5A, the surface of the substrate to which the die is bonded can be referred to as the “upper” surface, and the metal layer on the surface can be referred to as the “upper” metal layer. However, the die mounting surface need not have any particular orientation in use.

  In the bottom BGA package of FIG. 5A, the dice are wire bonded onto the wire bond site of the upper metal layer of the substrate to form an electrical connection. The die 414 and wire bond 416 are encapsulated with a molding compound 417 that provides protection from ambient and mechanical stresses to facilitate processing operations. A bottom package upper surface 419 is then provided on which a second (“top”) package can be stacked. The solder balls 418 are reflowed onto a molding pad on the metal layer on the underside of the board to provide interconnection with the underlying electrical circuitry of the final product motherboard (not shown), eg, a computer. The Solder masks 415 and 427 are formed on the metal layers 421 and 423 so as to expose the basic metal at connection positions for electrical connection. For example, the wire bond site and the connection pad are for connecting the wire bond 416 and the solder ball 418.

  In the form shown in FIG. 5A, the top package 500 is a land grid array (“LGA”) package, similar to the BGA package illustrated in FIG. However, it does not have solder balls placed on the connection pads on the lower surface of the substrate. In this example, the top package 500 in particular includes a die 514 that is mounted on a top package substrate 512 having at least one metal layer. Any of a variety of substrate types can be used. The top package substrate 512 illustrated in FIG. 5A has two metal layers 521 and 523, each formed to supply a special electric circuit and connected to each other by a bias 522. The die is commonly referred to as a die attach epoxy and is adhered to the surface of the substrate using an adhesive shown at 513 in FIG. 5A. In the configuration of FIG. 5A, the surface of the substrate to which the dice is bonded is referred to as the “upper” surface, and the metal layer on the surface is referred to as the “upper” metal layer. However, the die mounting surface need not have any particular orientation in use.

  In the top LGA package shown in FIG. 5A, the dice are wire bonded onto the wire bond site on the upper metal layer of the substrate to form an electrical connection. The die 514 and the wire bond 516 are encapsulated by a molding compound 517 that provides protection against ambient and mechanical stresses to facilitate processing operations. The molding compound includes a top package upper surface 519. The top package 500 is stacked on the bottom package 400 and bonded using an adhesive 503. The solder masks 515 and 527 are formed on the metal layers 521 and 523 so that the basic metal is exposed at the connection positions for electrical connection. For example, the wire bond site is for connecting wire bonds 516.

  The z-axis interconnection between the top package 500 and the bottom package 400 stacked on the bottom package 400 is formed by wire bonds 518 connected to the upper metal layer of the respective package substrate. One end of each wire bond 518 is electrically connected to the pad upper surface of the upper metal layer 521 of the top package substrate 512. The other end of each wire bond is connected to the pad upper surface of the upper metal layer 421 of the bottom package substrate 412. The wire bond may be formed by any wire bond technique, but may be formed by a known technique, for example, as described in U.S. 5,226,582 referenced herein. The z-axis interconnect wire bond between the packages is welded or crimped to the upper surface of the pad on the top metal layer of the top substrate and then pulled downwardly from the pad on the upper metal layer of the bottom substrate. It is shown as an example in FIG. 5A as being formed by melting. Preferably, the wire bonds can be formed in the opposite direction. That is, it can be formed by welding or crimping to the upper surface of the pad on the upper metal layer of the bottom substrate, and then drawing the wire upward from there and melting it on the pad on the upper metal layer of the top substrate. . Preferably, the selection of the z-axis interconnect wire bond configuration between the packages is determined according to the geometrical arrangement of the edges of the stacked substrates and their connection surfaces.

  In the stacked package configuration of FIG. 5A, the z-axis interconnect pads of each package substrate are located on the upper metal layer near the edge of the package substrate. The location and arrangement of the z-axis interconnect pads are generally arranged such that when the packages are stacked, the z-axis interconnect pads of the top package substrate lie on the corresponding z-axis interconnect pads of the bottom package. ing. Preferably, the top package 500 has a substrate upper surface space that is smaller than the substrate upper surface space of the bottom package 400 to provide clearance for wire bonds so as not to be electrically shorted to the edge of the metal layer of the substrate. Once the z-axis interconnect wire bond is formed, the module's capsule is formed and the z-axis interconnect wire bond is enclosed and protected to provide mechanical integrity to the finished module.

  The arrangement of the z-axis interconnect pads on the top and bottom package substrates is shown generally at 500 and 400 illustrated in FIGS. 5B and 5C, respectively. As shown in FIG. 5B, the top package z-axis interconnect pads 524 are formed by patterning the portion of the upper metal layer located at the edge 501 of the upper surface 525 of the top package substrate 512. The edge 501 extends beyond the edge 526 of the top package capsule body with the upper surface 519. As shown in FIG. 5C, the bottom package z-axis interconnect pads 424 are formed by patterning the portion of the upper metal layer located at the edge 401 of the upper surface 425 of the top package substrate 412. The edge 401 extends beyond the upper surface space 511 of the stacked and lying top package substrate 512 and extends further beyond the edge 426 of the bottom package encapsulant material comprising the upper surface 419.

  As is apparent from FIGS. 5A, 5B, and 5C, the z-axis interconnection between the top package and the bottom package according to the present invention is such that the top package interconnect pad 524 and the bottom package substrate at the edge 501 of the top package substrate. It is formed by a wire bond between the bottom package interconnection pad 424 of the edge 401 (either an upper connection or a lower connection). The configuration of the multi-package module is protected by the structure of the module capsule body 507, and the solder balls 418 are provided on the underside of the bottom package substrate for connection to a basic electrical circuit such as a motherboard (not shown). Reflowed over the solder ball pads exposed in the metal layer.

  As can be appreciated from the above, the configuration according to the present invention allows both BGA and LGA pretests prior to assembly of the multi-package module, and also discards non-conforming packages prior to assembly. to enable. Thereby, a high final module test yield can be ensured.

  A heat spreader is provided on the top package to improve heat dissipation from the multi-package module. The top heat spreader is formed from a thermally conductive material and at least a more central region of its upper surface is exposed towards the periphery on the upper surface of the MPM for efficient heat exchange away from the MPM. . The top heat spreader is, for example, a metal plate (such as copper) that is attached to the MPM capsule body during the molding material curing process. Alternatively, the heat spreader has a substantially flat portion on the top package and a peripheral support portion or support member disposed on or near the upper surface of the bottom package substrate.

  As an example, FIG. 5E is a cross-sectional view illustrating a BGA + LGA MPM 54 according to another aspect of the present invention. Among them, a “top” heat spreader is provided on the upper surface of the MPM. The configuration of the stacked packages in the MPM 54 is generally the same as the configuration of the MPM 50 in FIG. The top heat spreader in this example is made of a thermally conductive material and has a substantially flat central portion 544 located above the top package and a peripheral support 546 extending toward the upper surface of the bottom package substrate 412. doing. The upper surface of the planar portion 544 is exposed towards the periphery at the MPM upper surface for efficient heat exchange away from the MPM. The top heat spreader is formed, for example, by punching from a metal plate (such as copper). The support 546 can optionally be attached to the upper surface of the bottom package substrate using an adhesive (not shown). The configuration of the multi-package module is protected by the configuration of the module capsule body 507, and the heat spreader support is enclosed in the MPM capsule body 507 during the molding material curing process. As shown in FIG. 5E, steps such as recesses 545 are fed around the upper planar portion 544 of the heat spreader, thus reducing layer cracking from the molding compound and providing a more mechanical completeness for the structure. Sex can be obtained. In this embodiment, the gap between the lower surface of the heat spreader 544 and the upper surface of the LGA mold 917 is filled with a thin layer of MPM mold.

  Alternatively, as shown in the cross-sectional view of FIG. 5D, the top heat spreader can be attached to the upper surface of the LGA mold. The configuration of the packages stacked in the MPM 52 is generally the same as the configuration of the MPM 50 in FIG. 5A, and the same configuration is identified by reference numerals in the drawings. The top heat spreader 504 in FIG. 5D is substantially the same as in FIG. 5E, with a thermally conductive material with at least a more central region of its upper surface exposed to the surroundings for efficient heat exchange away from the MPM. It is flat. The top heat spreader is, for example, a metal plate (such as copper). Here, however, the top heat spreader 504 is attached to the upper surface 519 of the upper package capsule body 517 using an adhesive 506. Adhesive 506 is a thermally conductive adhesive because it provides improved heat dissipation. Typically, the top heat spreader is attached to the top package mold after the top package mold has been at least partially cured and before the molding material is injected into the MPM capsule body 507. The periphery of the top heat spreader is encapsulated by MPM molding material. In the form of FIG. 5D, steps such as recesses 505 can be applied to the outer shape of the heat spreader 504 to reduce layer cracking from the molding compound and obtain more mechanical integrity for the structure.

  As a further alternative, an MPM as in FIG. 5A can simply supply a planar heat spreader without a support. It is not attached to the upper surface of the top package mold. In such a form, as in the form of FIG. 5D, the top heat spreader is substantially flat made of a thermally conductive material such as a metal plate (for example, copper). Then, at least the central region of the upper surface of the flat heat spreader is exposed toward the periphery in order to perform efficient heat exchange away from the MPM. Here, the gap between the lower surface of the simply planar heat spreader and the upper surface 519 of the LGA mold 517 is filled with a thin layer of MPM mold. Such simply planar heat spreaders are then attached to the MPM capsule body 507 during the molding material curing process. The perimeter of a simply planar top heat spreader that is not so attached is encapsulated by MPM molding material, like the attached planar heat spreader of FIG. And can reduce layer cracking from the molding compound to obtain more mechanical integrity in the structure.

  As shown in FIGS. 5D and 5E, an MPM structure having a heat spreader provides improved thermal performance.

  FIG. 6A shows a cross-sectional view of stacked packages of multi-package modules according to an embodiment of the present invention, in which an LGA top package is stacked on a BGA bottom package. Among them, the top package LGA is partially encapsulated. The molding material of the top LGA package is applied in a limited range and in a limited amount and is sufficient to protect the wire bonds in later processing, especially in later operational tests. For other matters, the configuration of FIG. 6A is shown in FIG. 5A. Accordingly, in this configuration, the bottom package 400 is configured as detailed in FIG. 5A, and the top package 600 is generally as detailed in FIG. 5A, except for the difference in the top package capsule. Composed. In particular, the bottom package 600 comprises a die 614 that is mounted on a top package substrate 612 having at least one metal layer. Note that any of a variety of substrate types can be used. The top package substrate 612 illustrated in FIG. 6A has two metal layers 621 and 623, each formed to supply a special electric circuit and connected to each other by a bias 622. The dies are typically bonded to the surface of the substrate using an adhesive commonly referred to as a die attach epoxy, shown at 613 in FIG. 6A. Then, in the configuration of FIG. 6A, the surface of the substrate to which the dice is bonded can be referred to as the “upper” surface, and accordingly the metal layer on the substrate is the “upper” or “top” metal layer. Can be called. However, the die mounting surface need not have any particular orientation in use.

  In the top LGA package shown in FIG. 6A, the dice are wire bonded onto the wire bond site on the upper metal layer of the substrate to form an electrical connection. The die 614 and wire bond 616 are encapsulated by a molding compound 617 that provides protection against ambient and mechanical stresses to facilitate processing operations. In this embodiment, the capsule body 617 is formed so as to wrap only the connection points of the wire bond, the top package substrate, and the top package die so that most of the upper surface of the die 614 is not covered by the capsule body. . The top package 600 is placed on the bottom package 400 and bonded using an adhesive. The solder masks 615 and 627 are formed on the metal layers 621 and 623 so that the base metal is brought into contact at a connection position for electrical connection. For example, the wire bond site is for connecting wire bonds 616.

  The z-axis interconnect between the stacked top package 600 and bottom package 400 is formed by wire bonds 618 connecting to the upper metal layer of each package substrate. The configuration of the multi-package module is protected by the structure of the module capsule 607, and the solder balls 418 are connected to a basic electrical circuit such as a mother board (not shown), so that the metal on the lower side of the bottom package substrate Reflowed over the solder ball pads exposed in the layer.

  The advantage of this configuration is that costs are reduced. Partial encapsulation is performed in line with a wire bond process (eg, dispensing through a thin nozzle, dispensing from a syringe through a hollow needle), resulting in higher throughput and reduced encapsulant usage. . After partial encapsulation, the top LGA package can be tested without using special processing to avoid damaging the top package wire bonds.

  In order to improve heat dissipation from a multi-package module as illustrated in FIG. 6A, a heat spreader is supplied over the top package. The top heat spreader is formed from a thermally conductive material and at least a more central region of its upper surface is exposed towards the periphery on the upper surface of the MPM for efficient heat exchange away from the MPM. . The top heat spreader is, for example, a metal plate (such as copper) that is attached to the MPM capsule during the molding material curing process. Alternatively, the heat spreader has a substantially flat portion on the top package and a peripheral support or support member disposed on or near the upper surface of the bottom package substrate.

  As an example, FIG. 6B is a cross-sectional view illustrating a BGA + LGA MPM 62 according to another embodiment of the present invention. Among them, a “top” heat spreader is provided on the upper surface of the MPM. The configuration of the packages stacked in MPM 62 is generally similar to the configuration of MPM 60 in FIG. 6A, and similar configurations are identified by reference numerals in each figure. The top heat spreader in this example is formed of a thermally conductive material and includes a substantially flat central portion 644 located on the top package and a peripheral support portion 646 extending toward the upper surface of the bottom package substrate 412. Have. The upper surface of the planar portion 644 is exposed towards the periphery at the MPM upper surface for efficient heat exchange away from the MPM. The top heat spreader is formed from, for example, a metal plate (such as copper), and is formed by punching, for example. Support 646 can optionally be attached to the upper surface of the bottom package substrate using an adhesive (not shown). The configuration of the multi-package module is protected by the configuration of the module capsule body 607, and the heat spreader support is encapsulated in the MPM capsule body 607 during the molding material curing process. In the configuration of FIG. 6B, steps such as recesses 645 are fed to the outer periphery of the upper planar portion 644 of the heat spreader to reduce layer cracking from the molding compound to obtain more mechanical integrity for the structure. be able to. In this configuration, the space between the lower surface of the heat spreader 644 and the upper surface of the die 614 is filled with a layer of MPM mold. And since the layer is thin enough, the heat spreader 644 does not interfere with the periphery of the LGA mold 617.

  Also, the MPM as in the configuration of FIG. 6A can be provided with a planar heat spreader without a support. It is not attached to the upper surface of the top package mold. In such a form, as in the form of FIG. 5D, the top heat spreader is substantially flat made of a thermally conductive material such as a metal plate (for example, copper). Then, at least the central region of the upper surface of the flat heat spreader is exposed toward the periphery in order to perform efficient heat exchange away from the MPM. Here, in the configuration of FIG. 6B, the gap between the lower surface of the planar heat spreader and the upper surface of the die 614 is filled with a layer of MPM mold. And since it is thin enough, the heat spreader 644 does not interfere with the periphery of the LGA mold 617. And here, as in the form of FIG. 6B, such a simply planar heat spreader is attached to the MPM capsule body 607 during the molding material curing process. The periphery of such a non-attached simply planar top heat spreader may be provided with steps such as indentations on the outer periphery, such as the attached planar heat spreader of FIG. 5D, thereby allowing the MPM molding material Can also be encapsulated and can reduce layer cracking from the molding compound to provide more mechanical integrity for the structure.

  Further alternatively, in the configuration shown in FIG. 6A, a spacer is simply provided between the lower surface of the planar top heat spreader and the upper surface of the die 614 to allow connection of the planar heat spreader to the top package 600. Is provided. The spacer is attached to the die and the heat spreader using an adhesive. Alternatively, the spacer is formed as an entire heat spreader or a spacer portion. In such a configuration, the lower surface of the spacer portion of the heat spreader is attached to the upper surface of the die using an adhesive. The spacer is preferably a thermally conductive material, and the adhesive may be a thermally conductive adhesive to provide improved heat dissipation. In such a form, the top heat spreader is attached to the top package mold after the top package mold is at least partially cured and before the molding material is injected into the MPM capsule body 607. The outer shape of the top heat spreader is encapsulated with an MPM molding material. As in the form of FIG. 5D, steps such as indentations are simply fed to the outer periphery of the planar heat spreader to reduce layer cracking from the molding compound and obtain more mechanical integrity for the structure. it can.

  As illustrated in FIG. 6B, an MPM structure having a heat spreader can provide improved thermal performance.

  FIG. 7 is a cross-sectional view illustrating stacked multi-package modules according to another embodiment of the present invention. In FIG. 7, the top LGA package is stacked on the BGA bottom package, and a substrate that is a single metal layer is used as the top LGA package. In other respects, the configuration shown in FIG. 7 is substantially shown in FIG. 5A. Thus, in this configuration, the bottom package 400 is configured as detailed in FIG. 5A, and the top package 700 is as detailed in FIG. 5A, except for the difference in the configuration of the top package substrate. Generally composed. In particular, the top package 700 includes a die 714 that is mounted on a top package substrate 712 having a single metal layer 721 and is configured to supply a special electrical circuit. The die is commonly referred to as a die-bonded epoxy and is bonded to the surface of the substrate using an adhesive shown at 713 in FIG. In the configuration of FIG. 7, the surface of the substrate to which the dice is bonded is referred to as the “upper” surface, and the metal layer on the surface is referred to as the “upper” metal layer or the “top” metal layer. However, the die mounting surface need not have any particular orientation in use.

  In the top LGA package shown in the form of FIG. 7, the dice are wire bonded onto the wire bond site on the upper metal layer of the substrate to form an electrical connection. The die 714 and wire bond 716 are encapsulated by a molding compound 717 that provides protection against ambient and mechanical stresses to facilitate processing operations. The capsule body 717 in the configuration shown in FIG. 7 covers not only the dice but also wire bonds and their connections, and the capsule body has a surface 719 on the entire die and interconnects as in the configuration of FIG. 5A. Formed. Preferably, the capsule may instead be formed as shown in the configuration of FIG. 6A. That is, it may be formed so as to wrap only the connection points of the wire bond, the top package substrate, and the top package die. Thus, much of the upper surface of the die is not covered by the capsule body. The top package 700 is stacked on the bottom package 400 and bonded using an adhesive indicated by reference numeral 703. The solder mask 715 is formed on the metal layer 721 so that the base metal is exposed at a connection position for electrical connection. For example, the wire bond site is for connecting wire bonds 716.

  The z-axis interconnect between the stacked top package 700 and bottom package 400 is formed by wire bonds 718 that connect to the upper metal layer of each package substrate. The configuration of the multi-package module is protected by the structure of the module capsule body 707, and the solder balls 418 are connected to a basic electric circuit such as a mother board (not shown), so that the metal under the bottom package substrate is provided. Reflowed over the solder ball pads exposed in the layer.

  The advantage of this configuration is that the cost is reduced due to the low cost of the substrate consisting of one metal layer compared to the case where the top LGA package has a substrate consisting of two metal layers. is there. Furthermore, this configuration provides a low package profile because a substrate made of a single metal layer is thinner than a substrate having two or more metal layers.

  FIG. 8 is a cross-sectional view showing a BGA + LGA MPM 80 according to another embodiment of the present invention. Among them, the heat spreader and the electric shielding material are provided in the bottom package. The form illustrated in FIG. 8 includes a topland grid array (“LGA”) package 800 stacked on a bottom ball grid array “BGA” package 402. Among them, the top LGA package is generally configured like the top LGA package shown in FIG. 5A. Preferably, an LGA with only a single metal layer as detailed in FIG. 6A can be used instead of the top LGA in the configuration of FIG. 8A. In FIG. 8A, the top package 800 is similar to the BGA package illustrated in FIG. However, it does not have solder balls placed on the connection pads on the lower surface of the substrate. In particular, in this example, the top package 800 comprises a die 814 that is attached to a top package substrate 812 having at least one metal layer. Note that any of a variety of substrate types can be used. The top package substrate 812 illustrated in FIG. 8A has two metal layers 821, 823, each formed to supply a special electrical circuit and connected to each other by a bias 822. The dies are commonly referred to as die bonded epoxies and are bonded to the surface of the substrate using an adhesive shown at 813 in FIG. 8A. 8A, the surface of the substrate to which the die is bonded is referred to as the “upper” surface, and the metal layer on that surface is referred to as the “upper” or “top” metal layer. However, the die mounting surface need not have any particular orientation in use.

  In the top LGA package shown in the form of FIG. 8A, the dice are wire bonded onto the wire bond sites on the upper metal layer of the substrate to form an electrical connection. The die 814 and the wire bond 816 are encapsulated by a molding compound 817 that provides protection against ambient and mechanical stresses to facilitate processing operations. The solder masks 815 and 827 are formed on the metal layers 821 and 823 so that the base metal is exposed at a connection position for electrical connection. For example, the wire bond site is for connecting wire bonds 816.

  In the form of FIG. 8A, the bottom BGA package 402 is supplied by a heat spreader that is not encapsulated by a molding compound, but instead can further function as an electrical shield, as described below. Except for this, it is a conventional BGA package as shown in FIG. Thus, in this form, the bottom package 402 comprises a die 414 that is mounted on a bottom package substrate 412 having at least one metal layer. Note that any of a variety of substrate types can be used. For example, a laminate having 2 to 6 metal layers, or a substrate having 4 to 8 metal layers, or a flexible polyimide tape having 1 or 2 metal layers, or a ceramic multilayer substrate is also included. The bottom package substrate 412 illustrated in FIG. 8A has two metal layers 421 and 423, each formed to supply a special electrical circuit and connected to each other by a bias 422. The dies are typically adhered to the surface of the substrate using an adhesive commonly referred to as a die attach epoxy, shown at 413 in FIG. 8A. In the configuration of FIG. 8A, the surface of the substrate to which the dice is bonded is referred to as the “upper” surface, and the metal layer on the surface is referred to as the “upper” metal layer. However, the die mounting surface need not have any particular orientation in use.

  In the bottom BGA package shown in FIG. 8A, the dice are wirebonded to wirebond sites on the upper metal layer of the substrate to form an electrical connection. Solder balls 418 are reflowed over the molding pads on the metal layer on the underside of the board to provide interconnection with the underlying electrical circuitry of the final product motherboard (not shown), eg, a computer. The Solder masks 415 and 427 are formed on the metal layers 421 and 423 so as to expose the basic metal at connection positions for electrical connection. For example, the wire bond site and the connection pad are for connecting the wire bond 416 and the solder ball 418.

  The bottom BGA package 402 of the multi-package module 80 includes a metal (for example, copper) heat spreader. It further functions as an electrical shield for electrically suppressing electromagnetic radiation from the lower BGA die. As a result, interference with the upper package die is prevented. The “top” planar portion of the heat spreader 406 is supported by legs or sidewalls 407 on a die 414 on the substrate 412. The adhesive spot or line 408 serves to attach the heat spreader support 407 to the upper surface of the bottom substrate. The adhesive can be a conductive adhesive and can be electrically connected to the metal layer 421 on the top side of the substrate 412 and in particular to the ground layer of the circuit. As a result, a heat spreader as an electrical shielding material is formed. Alternatively, the adhesive can be an adhesive that does not have electrical conductivity, and in such a configuration, the heat spreader functions only as a heat spreader. The support and top surface of the heat spreader 406 surrounds the die 414 and the wire bond 416, and from ambient and mechanical stress to facilitate processing operations, especially during testing prior to MPM assembly. It serves to protect the structure.

  The top package 800 of the multi-package module 80 is stacked on the bottom package 402 on the plane of the heat spreader / shield 406 and attached using an adhesive 803. In order to improve heat dissipation, the adhesive 803 is thermally conductive. The adhesive 803 can then be conductive in order to form an electrical connection of the heat spreader 406 to the lower metal layer of the LGA package substrate. Or since it is electrically insulated, an electrical connection can be prevented.

  The z-axis interconnection between the top package 800 and the bottom package 402 according to the present invention is between the top package interconnect pad at the edge of the top package substrate 812 and the bottom package interconnect pad at the edge of the bottom package substrate 402. Formed by wire bond 818. Wire bonds are formed with either up or down connections. The configuration of the multi-package module is protected by the structure of the module capsule body 807. The gap is formed by the heat spreader support 407 to provide MPM molding material to fill the enclosed space during encapsulation.

  The solder balls 418 are reflowed onto the solder ball pads exposed on the lower metal layer of the bottom package substrate for connection to a basic electrical circuit such as a motherboard (not shown).

  As described above, the configuration of the present invention allows both BGA and LGA pre-tests prior to assembly of the multi-package module, and allows the disposal of non-conforming packages prior to assembly. Thereby, a high final module test yield can be ensured.

  In order to improve the heat dissipation from the multi-package module, a heat spreader can be provided on the top package. The top heat spreader is formed from a thermally conductive material and at least a more central region of its upper surface is exposed towards the periphery on the upper surface of the MPM for efficient heat exchange away from the MPM. . The top heat spreader is, for example, a metal plate (such as copper) that is attached to the MPM capsule body during the molding material curing process. Alternatively, the heat spreader has a substantially flat portion on the top package and a peripheral support or support member disposed on or near the upper surface of the bottom package substrate.

  As an example, FIG. 8B is a cross-sectional view illustrating a BGA + LGA MPM 82 according to another aspect of the present invention. Among them, a “top” heat spreader is provided on the upper surface of the MPM. The configuration of the packages stacked in the MPM 82 is generally similar to the configuration of the MPM 80 in FIG. 8A, and similar configurations are identified by the reference numerals in each figure. The top heat spreader in this example is formed of a thermally conductive material, and includes a substantially flat central portion 804 located on the top package and a peripheral support portion 806 extending toward the upper surface of the bottom package substrate 412. Have. The upper surface of the planar portion 804 is exposed towards the periphery at the MPM upper surface for efficient heat exchange away from the MPM. The top heat spreader is formed from, for example, a metal plate (such as copper), and is formed by punching, for example. The support 806 can optionally be attached to the upper surface of the bottom package substrate using an adhesive (not shown). The configuration of the multi-package module is protected by the configuration of the module capsule body 807, and the heat spreader support is enclosed in the MPM capsule body 807 during the molding material curing process. In the configuration of FIG. 8B, a step such as a recess 805 is fed to the outer periphery of the upper planar portion 804 of the heat spreader to reduce layer cracking from the molding compound to obtain more mechanical integrity for the structure. be able to. In this configuration, the space between the lower surface of heat spreader 804 and the upper surface 819 of LGA mold 817 is filled with a thin layer of MPM mold.

  Alternatively, the top heat spreader does not have a support and may be a generally planar material of a thermally conductive material such as, for example, a metal plate (such as copper). At least the more central region of the upper surface of the planar heat spreader is exposed to the environment for efficient heat exchange away from the MPM. Such a simple planar heat spreader is shown at 844 in FIG. 8C when the heat spreader is attached to the upper surface of the top package mold. However, in FIG. 8B, the heat spreader is not connected to the upper surface of the top package mold. Instead, the space between the lower surface of the simply planar heat spreader and the upper surface 819 of the LGA mold 817 is filled by a thin layer of the MPM mold, and such simply planar heat spreader is hardened with the molding material. Attached to the MPM capsule body 807 during processing. The outline of a simply planar top heat spreader can be encapsulated with an MPM molding material in a configuration such as FIG. 8B. Steps such as indentations on the outer periphery (see indentation 845 in a simply planar top heat spreader 844 shown in FIG. 8C) to reduce layer cracking from the molding compound and to obtain more mechanical integrity about the structure ).

  Alternatively, as shown in the cross-sectional view of FIG. 8C, the top heat spreader can be attached to the upper surface of the LGA mold. The configuration of packages stacked in MPM 84 is generally similar to the configuration of MPM 80 in FIG. 8A, and similar configurations are identified by reference numerals in each figure. The top heat spreader 844 in FIG. 8C is substantially the same as in FIG. 8B, and is a heat conductive material in which at least a more central region of its upper surface is exposed to the surroundings for efficient heat exchange away from the MPM. It is flat. The top heat spreader is, for example, a metal plate (such as copper). Here, however, the top heat spreader 804 is attached to the upper surface 819 of the upper package capsule body 817 using an adhesive 846. Adhesive 846 is a thermally conductive adhesive because it provides improved heat dissipation. Typically, the top heat spreader is attached to the top package mold after the top package mold has been at least partially cured and before the molding material is injected into the MPM capsule body 847. The periphery of the top heat spreader is encapsulated by MPM molding material. In the configuration of FIG. 8C, steps such as indentations 845 can be applied to the outer shape of the heat spreader 844 to reduce layer cracking from the molding compound to obtain more mechanical integrity for the structure.

  The advantages of the configuration as shown in FIGS. 8A, 8B, 8C are effective thermal performance and electrical shielding in any bottom package. And it can be a particularly serious crisis. For example, in MPM, it connects RF and digital chips. It is not necessary to have both a bottom package heat spreader and a top heat spreader for every application. Either one or the other is used depending on the needs of the final product.

  FIG. 9A is a cross-sectional view showing a multi-package module according to another embodiment of the present invention. In this figure, flip-chip BGAs that are downward dies are stacked with LGAs. In the lower BGA, the die is a flip chip connected to the substrate, and the space between the die and the substrate is underfilled. This BGA can be tested before being incorporated into the MPM. The top LGA can be attached to the back surface of the die by an adhesive. The top LGA z-axis interconnect to the module substrate is made by wire bonding to form the MPM. The main advantage of this configuration is that the flip chip connection on the BGA has high electrical performance.

  With reference to FIG. 9A, the bottom BGA flip chip package comprises a substrate 312 having a patterned metal layer 321. On top of that, the die 314 is connected by a solder bump, a gold stud bump, or a flip chip bump 316 such as an anisotropically guiding film or paste. Note that any of a variety of substrate types can be used. The bottom package substrate 312 illustrated in FIG. 9A has two metal layers 321, 323, each formed to provide a suitable electrical circuit and connected by a bias 322. The flip chip ridge is a patterned array of raised pads on the functional surface of the die so that the functional surface of the die faces downward in relation to the metal layer patterned upward facing the substrate. Attached to. Such an arrangement can be referred to as a downward die flip chip package. The polymer underfill 313 between the die and the substrate provides protection from the surroundings and adds mechanical integrity to the structure.

  The top LGA package 900 of the multi-package module 90 is generally configured similar to the top LGA package 700 of the multi-package module 70 shown in FIG. In particular, the top package 900 comprises a die 914 that is mounted on a top package substrate 912 having a single metal layer 921 that is patterned to provide a suitable electrical circuit. The dies are typically adhered to the surface of the substrate using an adhesive commonly referred to as a die attach epoxy, shown at 913 in FIG. 9A. Then, in the configuration of FIG. 9A, the surface of the substrate to which the dice is bonded can be referred to as the “upper” surface, and the metal layer on this substrate is accordingly the “upper” metal layer or “top” metal. It can be called a layer. However, the die mounting surface need not have any particular orientation in use.

  In the top LGA package in the form of FIG. 9A, the dice are wire bonded to wire bond sites on the upper metal layer of the substrate to form electrical connections. The die 914 and wire bond 916 are encapsulated with a molding compound 917 that provides protection from ambient and mechanical stresses to facilitate processing operations. The capsule body 917 in the configuration shown in FIG. 9A covers not only the dice, but also wire bonds and their connections, and the capsule body has a surface 919 on the entire die and interconnects. Preferably, instead of this capsule body, it may be formed as shown in the form of FIG. 6A. That is, it may be formed so as to enclose only the respective connections of the wire bond, the top package substrate and the top package die. Therefore, many of the upper surfaces of the dies may not be covered by the capsule body. The top package 900 is stacked on the bottom package 300 and attached using an adhesive indicated by 903. The solder mask 915 is formed on the metal layer 921 so as to expose the underlying metal at a connection position for electrical connection, for example, at a wire bond site for connecting the wire bond 916.

  The z-axis interconnect between the stacked top package 900 and bottom package 300 is formed via wire bonds 918 connecting the top metal layers of the respective package substrates. The configuration of the multi-package module is protected by the configuration of the module capsule body 907. The solder balls 318 are reflowed onto the exposed solder ball pads of the metal layer under the bottom package substrate for connection to basic electrical circuitry such as a final product motherboard (not shown) such as a computer. The Solder masks 315 and 327 are formed on the metal layers 321 and 323 so as to expose the basic metal at connection positions for electrical connection. For example, the wire bond site and the connection pad are for connecting the wire bond 918 and the solder ball 318.

  A configuration having an LGA stacked on top of a flip-chip BGA in a downward facing die detailed as an example in FIG. 9A is generally assembled by a heat spreader / electrical shield as shown in FIG. 8B or 8C. obtain. Accordingly, FIG. 9B is a cross-sectional view illustrating a multi-package module according to another embodiment of the present invention. Therefore, the flip chip BGA in the downward die state is stacked with the LGA as shown in FIG. 9A, and the heat spreader / shielding material is supplied to the lower BGA.

  In particular, as shown in FIG. 9B, the bottom BGA package 300 of the multi-package module 92 is provided with a metal (eg, copper) heat spreader. It further functions as an electrical shield to electrically suppress any electromagnetic radiation from the die in the lower BGA. As a result, interference with the die is prevented in the upper package. The “top” planar portion of the heat spreader 906 is supported by legs or sidewalls 909 above the substrate 312 and above the die 314. The adhesive spot or line 908 serves to attach the heat spreader support 909 to the upper surface of the bottom substrate. The adhesive can be a conductive adhesive and can be electrically connected to the top metal layer 321 of the substrate 312, in particular to the ground plane of the circuit. Therefore, a heat spreader can be established as an electrical shielding material. Alternatively, the adhesive can be non-conductive, and in such a configuration, the heat spreader acts only as a heat spreader. The support and top of the heat spreader 906 surround the die 314 and help to facilitate processing operations, and in particular to protect against ambient and mechanical stress during testing prior to assembling the MPM.

  The top package 900 of the multi-package module 92 is stacked on the bottom package 300 on the plane of the heat spreader / shield 906 and attached using an adhesive 903. Adhesive 903 can be thermally conductive to improve heat dissipation. Also, the adhesive 903 can be conductive to form an electrical connection between the lower metal layer of the LGA package substrate and the heat spreader 906. Or it can be set as the electrically insulated state, As a result, an electrical connection can be prevented.

  The z-axis interconnection between the top package 900 and the bottom package 300 according to the present invention is between the top package interconnect pad at the edge of the top package substrate 912 and the bottom package interconnect pad at the edge of the bottom package substrate 300. Formed by wire bond 918. The wire bond may be formed by either an upper connection or a lower connection method. The configuration of the multi-package module is protected by the configuration of the module capsule body 907. The gap is provided by the heat spreader support 907 to fill the space surrounded by the MPM molding material during encapsulation.

  The solder balls 318 are reflowed onto the exposed solder ball pads on the lower metal layer of the bottom package substrate 300 for connection to a basic electrical circuit such as a motherboard (not shown).

  Preferably, the arrangement according to the present invention allows both BGA and LGA pre-tests prior to incorporation into a multi-package module, and allows the disposal of non-conforming packages prior to assembly. As a result, a high final module test yield can be ensured.

  The processor chip of the flip chip bottom package according to the present embodiment is, for example, an ASIC, GPU, or CPU, and an ASIC is often used. The top package is a memory package or an ASIC package. If the top package is a memory package, it may be a stacked dice memory package. The shielded flip chip downward die bottom package is particularly suitable for higher speed applications, particularly RF frequency processing similar to mobile communications applications.

  Additionally, an MPM having a flip chip bottom package with a downward die configuration (as shown in FIG. 9A or 9B) is provided with a heat spreader.

  As illustrated in FIG. 9A or 9B, a heat spreader is provided over the top package for improved heat dissipation from the multi-package module. The top heat spreader is formed from a thermally conductive material and at least a more central region of its upper surface is exposed towards the periphery on the upper surface of the MPM for efficient heat exchange away from the MPM. . The top heat spreader is, for example, a metal plate (such as copper) that is attached to the MPM capsule during the molding material curing process. Alternatively, the heat spreader has a substantially flat portion on the top package and a peripheral support or support member disposed on or near the upper surface of the bottom package substrate.

  FIG. 9C shown as an example is a cross-sectional view showing an MPM 94 in which BGA and LGA according to another embodiment of the present invention are stacked. There, a top heat spreader is provided on the upper surface of the MPM. The configuration of the stacked packages in MPM 94 is generally similar to the configuration of MPM 92 in FIG. 9B, and similar configurations are identified by reference numerals in the figures. The top heat spreader in this example is made of a thermally conductive material, and has a substantially flat portion 944 located on the top package and a peripheral support portion 946 extending toward the upper surface of the bottom package substrate 312. doing. The upper surface of the flat surface portion 944 is exposed toward the periphery on the upper surface of the MPM for efficient heat exchange away from the MPM. The top heat spreader is formed, for example, by punching from a metal plate (such as copper). The support 946 can optionally be attached to the upper surface of the bottom package substrate using an adhesive (not shown). The configuration of the multi-package module is protected by the configuration of the module capsule body 907, and the heat spreader support is fitted into the MPM capsule body 907 during the molding material curing process. In FIG. 9C, steps such as indentations 945 can be applied to the outer periphery of the heat spreader top plane 944 to reduce layer cracking from the molding compound to obtain more mechanical integrity for the structure. In this embodiment, the space between the lower surface of the heat spreader 944 and the upper surface of the die 914 is filled with a layer of MPM mold. The heat spreader 944 is sufficiently thick so as not to interfere with the surrounding LGA mold 917.

  Alternatively, an MPM as shown in FIG. 9A or 9B does not have a support and can simply be provided with a planar heat spreader. Such a simply planar heat spreader is attached to the upper surface 519 of the top package mold 517 using an adhesive. Alternatively, the MPM shown in FIG. 9A or 9B can be provided with a simple planar heat spreader that is not attached to the upper surface of the top package mold. In such a configuration, as shown in FIG. 5D, the top heat spreader can be substantially planar with a thermally conductive material such as, for example, a metal plate (such as copper). Then, at least the more central region of the upper surface of the planar heat spreader is exposed toward the periphery on the upper surface of the MPM in order to perform efficient heat exchange away from the MPM. Here, as shown in FIG. 9C, the space between the lower surface of the planar heat spreader and the top package 900 is filled with a layer of MPM. And now, as shown in FIG. 9C, such a simply planar heat spreader is attached to the MPM capsule body 907 during the molding material curing process. The perimeter of such a simply planar top heat spreader that is not connected may be encapsulated by the MPM molding material, as in the case of the connected planar heat spreader shown in FIG. 5D. Around that, a step such as a recess is provided to reduce layer cracking from the molding compound and to obtain more mechanical integrity for the structure.

  An MPM configuration with a heat spreader as illustrated in FIG. 9C can provide improved thermal performance.

  The MPM bottom package according to the present invention may be a flip chip package with an upward die configuration. In this case, the bottom package die is disposed on the lower surface of the bottom package substrate. Typically, such a bottom package die attach area is located in a substantially central area of the substrate, and the secondary interconnect balls are two or four (generally more) of the edges of the substrate. ) Is placed in the vicinity. The upward die flip chip and its flip chip interconnect configuration are located within the standoff height range of the secondary interconnect configuration, and accordingly the bottom package die in such configuration is the full thickness of the MPM. It does n’t contribute anything. Further, the upward die configuration can avoid the effect of reversing the netlist that generally results from the downward die configuration.

  In particular, by way of example, FIG. 10A is a cross-sectional view illustrating a multi-package module 101 according to another aspect of the present invention. In this case, the land grid array package 1000 on which the dies are stacked is stacked on the flip chip BGA of the upward die structure 302, and the stacked packages are interconnected by wire bonds. In the bottom BGA package 302, the dice 344 is attached to the lower side of the BGA substrate 342.

  As shown in the figure, this configuration provides a thinner MPM because the bottom package die is in the area between the solder balls located on the underside of the bottom package. Such a configuration not only because it comprises a flip-chip connection, but also a shorter metal trace, and a bias for the connection between the die and the solder ball (required for the configuration in FIG. 9A or 9B). Provides a more direct electrical connection to the solder balls of the die without the need for (as is), and can have higher electrical performance. Furthermore, the upward die configuration allows netlist compatibility for wire bonding in this package, as required by some applications. The netlist is the sum of all connection pairs between dies and solder balls. If the die faces upwards with a “downward die”, it has a connection pattern that is a mirror image pattern on the same die, as if the die faces downwards with an “upward die”. ing.

  In the configuration as shown in FIG. 10A, the top LGA package is adhesively attached to the top side of the BGA and then wire bonded and molded. In the form illustrated in FIGS. 10A-10E, one or more dies (two or more) are stacked in a top package. Stacked die packages are often installed in the industry as versions with up to five dies stacked in a package. The dies have various sizes, and the dies in the stacked die package have the same or relatively different sizes. The dies are generally square or rectangular, and rectangular or square dies of various dimensions are stacked in a stacked die package. If the die is rectangular or has various dimensions, the die should be such that the edge of the lower die stacked over the edge of the upper die stacked on it. Are stacked. As shown in FIG. 10A, the two stacked dies are the same size. In such a configuration, or when the stacked upper dies are larger than the lower dies, the spacers are assembled between the dies to allow wire bonding of all dies to the LGA substrate. FIG. 10B shows an example in which the stacked upper dies are smaller than the lower dies, or alternatively, the upper edges of the dies stacked so as to cross the stacked lower edges. Yes. In the configuration as in FIG. 10B, a spacer is not necessary. This is because the wire bond site at the projected edge of the lower die can be wire bonded without interference from the die stacked on it.

  As shown in FIG. 10A, the bottom flip chip BGA package 302 is connected to a die 344 by a solder bump, a gold stud bump, or a flip chip bump 346 such as an anisotropically guiding film or paste. A substrate 342 having a metal layer 353 patterned on the portion is provided. Any of a variety of substrate types can be used. The bottom package substrate 342 shown as an example in FIG. 10A has two metal layers 351, 353, each formed to provide a suitable electrical circuit. The bottom package substrate 342 further includes a metal layer 355 sandwiched between dielectric layers 354 and 356. The metal layer 355 has a void at a predetermined position so that the metal layers 351 and 353 can be connected with a bias. As a result, predetermined portions of the patterned metal layers 351, 353 are accordingly connected by bias through the substrate layers 354, 356 and through the voids of the sandwiched metal layer 355. A predetermined portion of the patterned metal layer 353 is connected to the sandwiched metal layer 355 through a substrate layer 356 by bias.

  Flip-chip ridges 346 are attached to the formed array of raised pads on the functional surface of the die, and the functional surface of the die faces upward with respect to the metal layer patterned facing down the substrate. Such an arrangement is referred to as an “upward die” flip chip package. A polymer underfill 343 between the die and the die attach area of the substrate provides protection from the surroundings and adds mechanical integrity to the configuration.

  As described above, the metal layers 351, 353 are patterned to provide a suitable electrical circuit, and the sandwiched metal layer 355 is between predetermined traces of the upper and lower metal layers 351, 353. In order to allow interconnection (no contact with the sandwiched metal layer 355), there is a void in place. In particular, for example, the lower metal layer is patterned in the die attachment area to provide an attachment location for the chip interconnect ridge 353. And, for example, the lower metal layer is patterned closer to the edge of the bottom package substrate 342 to provide a mounting location for the secondary interconnect solder balls 348. Thereby, the completed MPM is attached to a basic electrical circuit (not shown) by solder reflow. And in particular, for example, the upper metal layer is patterned near the edge of the bottom package substrate 342 to provide a mounting location for the wire bond connecting the top package with the bottom package. The ground line of the electric circuit of the metal layer 353 is connected to the sandwiched metal layer 355 through a bias. A predetermined one of the solder balls 348 is a ground ball. It is attached to the ground line of the basic electrical circuit when the MPM is attached. Thus, the sandwiched metal layer 355 serves as a ground plane for the MPM. Certain other of the solder balls 348 are input / output balls or power balls. Accordingly, they are attached in the electrical circuit of the metal layer 353 to solder ball locations on the input / output or power line, respectively.

  As shown in FIG. 10A, the top package 1000 is a stacked die land grid array package. It then has dice 1014, 1024 separated by spacers 1015 and stacked on top package substrate. The top package substrate comprises a dielectric layer 1012 having a metal layer on the surface of the upper substrate, and a wire bond interconnect of the top package substrate with stacked dies, eg 1031, and a bottom package substrate And a top package wire bond interconnect having a pattern to provide a mounting location. The lower die 1014 is attached to the die attachment area of the top package substrate using an adhesive 1013 such as die attach epoxy. The die 1014 is electrically connected to the top substrate by a wire bond 1016 that connects the wire bond site on the functional surface of the die to the wire bond site on the predetermined trace 1011. The spacer 1015 is attached to the upper surface of the lower die 1014 using an adhesive (not shown). The upper die 1024 is then attached to the upper surface of the spacer 1015 using an adhesive (not shown). The spacer is chosen to be thick enough to provide clearance so that the overhanging edge of the upper die 1024 does not hit the wire bond 1016. The die 1024 is electrically connected to the top substrate by a wire bond 1026 connecting the wire bond site on the functional surface of the die with the wire bond site on the predetermined trace 1011. The die and wire bond assembly stacked on the top package substrate is encapsulated with a molding material 1017 that provides the top package upper surface 1019 and leaves the periphery of the interconnect trace 1011 exposed. The The top package 1000 is tested at this point. It is then stacked on top of the die mounting area on the upper surface of the bottom package substrate and attached using adhesive 1003. The top and bottom package electrical interconnections connect the wire bond sites on the top metal substrate traces 351 of the bottom package substrate with the exposed wire bond sites on the top package substrate traces 1011. Caused by the wire bond 1018. The MPM assembly is then encapsulated with a mold 1007 to protect the wire bonds joining the packages and to provide mechanical integrity in the finished MPM 101.

  As described above, the die stop package stacked on the upward die flip chip BGA package in this embodiment has various configurations depending on, for example, the number of stacked dies and the dimensions of the dies. . For example, FIG. 10B shows an alternative MPM configuration 103 in its cross-sectional view. Among them, at least the LGA has two stacked dies and the upper die 1044 has a smaller dimension than the lower die 1034. In such a configuration, there is no protrusion of the upper die peripheral edge over the wire bond connection site at the edge of the lower die, and therefore it is not necessary to have a spacer. The bottom package 302 in the MPM 103 of FIG. 10B is substantially similar to the bottom package in the MPM 101 of FIG. 10A, and corresponding portions are similarly identified in each figure. The top package 1030 in the MPM 103 is a land grid array package of stacked dies, and includes dies 1034 and 1044 stacked on a top package substrate. The top package substrate includes a dielectric layer 1012 having a metal layer on the surface of the upper substrate. And patterned to provide a trace, eg, 1031, that is provided with a connection location for the wire bond interconnect of the top package substrate with stacked dies and the wire bond interconnect of the top package with the bottom package substrate. ing. The lower die 1034 is attached to the die connection area of the top package substrate using an adhesive 1033 such as a die connection epoxy. The die 1034 is electrically connected to the top substrate by a wire bond 1036 connecting a wire bond site and a wire bond site on the functional surface of the die on a predetermined trace 1031. Upper die 1044 is attached to the upper surface of lower die 1034 using adhesive 1035. The die 1044 is electrically connected to the top substrate by a wire bond 1046 connecting the wire bond site and the wire bond site on the functional surface of the die on a predetermined trace 1031. The stacked die and wire bond assembly on the top package substrate is encapsulated with molding material 1037 providing the top package upper surface 1039, leaving the peripheral portion of the interconnect trace 1031 exposed. Yes. The top package 1030 is tested at this point and then stacked on top of the die connection area on the upper surface of the bottom package substrate and attached using adhesive 1003. The electrical interconnection between the top package and the bottom package connects the wire bond site on the upper metal layer trace 351 of the bottom package substrate and the wire bond site exposed on the top package substrate trace 1031. Provided by wire bond 1018. The MPM assembly is then encapsulated by a mold 1007 to protect the wire bonds connecting between the packages and to provide mechanical integrity in the finished MPM 103.

  The processor chip in the flip chip bottom package according to this aspect of the invention can be, for example, an ASIC, GPU, or CPU. The top package can then be a memory package, for example, a stacked die memory package, particularly as described in FIGS. 10A and 10B. The flip chip upward die configuration for the bottom package can provide a very thin module and is particularly suitable for higher speed applications such as mobile communications.

  Preferably, the ground surface 355 of the bottom package substrate in the form of MPM 101 or 103 further serves as an electromagnetic shield to significantly reduce interference between the BGA die and the lying LGA die, and such MPM Is particularly useful in applications where the bottom package die is a high frequency (eg, radio frequency) die.

  In some applications, it is also preferable to shield the bottom package BGA dice from the underlying electrical circuit to which the MPM is connected. FIG. 10C shows an example of a multi-package module 105 in which stacked die land grid array packages 1000 are stacked on flip chip BGAs in an upward facing die configuration 302. And among them, the stacked packages are interconnected by wire bonds, and the electromagnetic shield flips to limit downward radiation towards the basic electrical circuit (not shown) Provided with chip BGA dice.

  In the MPM 105 in FIG. 10C, the top package 1000 and the bottom package 302 are roughly configured as the MPM 101 in FIG. 10A, and the corresponding functions are identified correspondingly in each figure. The bottom package 302 of the MPM 105 is provided with a metal (eg, copper) electrical shield to electrically suppress electromagnetic radiation from the lower BGA die. Therefore, interference with the electrical circuit under the attached MPM is prevented. The lower flat portion of the shield 304 is supported by legs or side walls 305. The adhesive spot or line 306 serves to attach the heat spreader support 305 to the lower surface of the bottom substrate. The adhesive can be a conductive adhesive and can be electrically connected to the traces of the metal layer on the underside of the substrate, in particular to the ground traces of the circuit. The shield support and the lower planar portion surround the die 344 and, in addition to shielding the lower die of the finished equipment, to facilitate processing operations and, in particular, before assembly of the MPM or It can help to protect the lower die from ambient and mechanical stress during pre-installation testing.

  Instead, as preferred, a shield as illustrated in FIG. 10C can be used to shield the upward die flip chip bottom package 302 in MPMs having other stacked die-stop package configurations. . As shown generally at 1030 in FIG. 10B, the stacked die-stop packages do not have any spacers between adjacent dies, for example.

  And alternatively, a shield as illustrated in FIG. 10C may be used to shield the upward die flip chip bottom package 302 of the MPM having a top package other than the stacked die stop package. . The top package is, for example, a land grid array package, such as the LGA top package shown generally as 500 in FIG. 5A.

  In addition, for improved heat dissipation from the multi-package module schematically illustrated in FIG. 10A, a heat spreader is provided on the top package. The top heat spreader is formed from a thermally conductive material, and at least a more central region of its upper surface is exposed to the periphery on the upper surface of the MPM for efficient heat exchange away from the MPM. The top heat spreader is, for example, a metal plate (such as copper) and is attached to the MPM capsule during the molding material curing process. Alternatively, the heat spreader has a substantially flat portion on the top package and a peripheral support portion or support member disposed on or near the upper surface of the bottom package substrate.

  As an example, FIG. 10E is a cross-sectional view showing an MPM 109 with a die stop package stacked on an upward die flip chip bottom BGA. In this, a “top” heat spreader is provided on the upper surface of the MPM. The configurations of the top package and the bottom package in the MPM 109 are generally similar to those of the MPM 105 in FIG. 10C, and similar configurations are identified by reference numerals in the drawings. The top heat spreader in this example is formed from a thermally conductive material having a generally planar central portion 1044 disposed on the top package 1000 and a peripheral support 1046 extending to the upper surface of the bottom package substrate 342. Is done. The upper surface of the planar portion 1044 is exposed to the surroundings at the MPM upper surface for efficient heat exchange away from the MPM. The top heat spreader is formed, for example, by punching from a metal plate (such as copper). The support 1046 can optionally be attached to the upper surface of the bottom package substrate using an adhesive (not shown). The configuration of the multi-package module is protected by the configuration of the module capsule body 1007. The heat spreader support is then enclosed in the MPM capsule body 1007 during the molding material curing process. In FIG. 10E, steps such as recesses 1045 can be applied to the outer periphery of the upper planar portion 1044 of the heat spreader to reduce layer cracking from the molding compound and to obtain more mechanical integrity for the structure. it can. In this configuration, the space between the lower surface of the heat spreader 1044 and the upper surface 1019 of the LGA mold 1017 is filled with a thin layer of MPM mold.

  Instead, the top heat spreader does not have a support portion, and may be a substantially planar one of a heat conductive raw material such as a metal plate (such as copper). At least the more central region of the upper surface of the planar heat spreader is exposed to the environment for efficient heat exchange away from the MPM. Such a simple planar heat spreader is shown at 1004 in FIG. 10D when the heat spreader is attached to the upper surface of the top package mold. The configuration of the stacked packages in the MPM 107 is the same as that of the MPM 109 in the schematic FIG. The top heat spreader 1004 in FIG. 10D is substantially the same as in FIG. 10E, with a thermally conductive material having at least a more central region of its upper surface exposed to the surroundings for efficient heat exchange away from the MPM. It is flat. The top heat spreader is, for example, a metal plate (such as copper). Here, however, the top heat spreader 1004 is attached to the upper surface 1019 of the upper package capsule body 1017 using an adhesive 1006. Adhesive 1006 is a thermally conductive adhesive to provide improved heat dissipation. Typically, the top heat spreader is attached to the top package mold after the top package mold has been at least partially cured and before the molding material is injected into the MPM capsule body 1007. The periphery of the top heat spreader is encapsulated by MPM molding material. In FIG. 10D, steps such as indentations 1005 can be applied to the outer periphery of the heat spreader 1004 to reduce layer cracking from the molding compound and obtain more mechanical integrity for the structure.

  A simply planar heat spreader such as 1004 in FIG. 10D need not be attached to the upper surface of the top package mold. Instead, the space between the lower surface of the simply planar heat spreader and the upper surface 1019 of the LGA mold 1017 is filled by a thin layer of MPM mold, such a simply planar heat spreader is used to cure the molding material. It is attached to the MPM capsule body 1007 during the treatment process. In such a configuration, simply the perimeter of the planar top heat spreader may be encapsulated by the MPM molding material, and to reduce layer cracking from the molding compound to obtain a more mechanical integrity of the structure. A step such as a recessed portion 1005 is provided on the outer periphery (see merely the recessed function 1005 of the planar heat spreader 1004 shown in FIG. 10D).

  An advantage of the configuration as in FIGS. 10D and 10E is improved thermal performance. It is not necessary to have both a bottom package shield and a top heat spreader in every application. Alternately one or the other is appropriate depending on the needs of the final product.

  FIG. 11 of the cross-sectional view generally shows another form of MPM according to the present invention as 110. Therein, the stacked dice LGA top package 1000 is stacked on the stacked dice BGA bottom package 408, and the top package and the bottom package are interconnected by wire bonds. In the configuration described in FIG. 11, the bottom BGA package 408 is stacked to include two dies, and the top LGA package is stacked to include two dies.

  A structure having this configuration is particularly preferred, for example, for applications that require high memory density in a fixed upper surface space. The stacked dies can be of the same type or different types, such as memory with flash, SRAM, PSRAM, etc.

  As shown in FIG. 11, the top package 1000 is configured substantially the same as the top package 1000 of FIG. 10A, and similar functions are identified by similar reference numerals. In particular, the top package 1000 is a stacked die land grid array package, and the dies 1014 and 1024 are separated by spacers 1015 and stacked on a top package substrate. The top package substrate includes a dielectric layer 1012 having a metal layer on the surface of the upper substrate. And patterned to provide traces, eg, 1011, that provide connection locations for the top bond substrate wirebond interconnect with stacked dies and the top package wirebond interconnect with the bottom package substrate. ing. The lower die 1014 is attached to the die mounting area of the top package substrate using an adhesive 1013 such as a die bonding epoxy. The die 1014 is electrically connected to the top substrate by a wire bond 1016 connecting a wire bond site on the functional surface of the die and a wire bond site on a predetermined trace 1011. The spacer 1015 is attached to the upper surface of the lower die 1014 using an adhesive (not shown), and the upper die 1024 is attached to the upper surface of the spacer 1015 using an adhesive (not shown). It is attached. The spacer is chosen to be thick enough to provide clearance so that the overhanging edge of the upper die 1024 does not hit the wire bond 1016. The die 1024 is electrically connected to the top substrate by a wire bond 1026 connecting the wire bond site on the functional surface of the die and the wire bond site on the predetermined trace 1011. The stacked die and wire bond assembly on the top package substrate is encapsulated with molding material 1017 providing the top package upper surface 1019, leaving the peripheral portion of the interconnect trace 1011 exposed. Yes. As described below, the top package 1000 is tested at this point and then stacked on the bottom package 408.

  The bottom package 408 of the MPM 110 is configured in the same manner as the top package 1000. In particular, the bottom package 408 is a stacked die land grid array package. Then, dies 444 and 454 separated by a spacer and stacked on the bottom package substrate are provided. The bottom package substrate serves as an interconnect substrate in the completed MPM, which can be configured in a manner similar to the bottom substrate 412 of the bottom package 400 of the MPM 50 of FIG. 5A, for example. In particular, in this form, the bottom package 408 has a bottom package substrate 442 comprising at least one metal layer. Any of a variety of substrate types can be used. For example, a laminate having 2 to 6 metal layers, or a substrate having 4 to 8 metal layers, or a flexible polyimide tape having 1 or 2 metal layers, or a ceramic laminated substrate is also included. The bottom package substrate 442 illustrated in FIG. 11 has two metal layers 451, 453, each patterned to provide an appropriate electrical circuit and connected by a bias 452. The lower die 444 is typically adhered to the “upper” surface of the substrate using an adhesive, commonly referred to as a die attach epoxy, shown at 443 in FIG. The lower die is electrically connected to the bottom substrate by wire bonds 446 connecting the wire bond sites on a given trace 451 and the wire bond sites on the functional surface of the die 444. The spacer is attached to the upper surface of the lower die 444 using an adhesive (not shown), and the upper die 454 is stacked and attached to the upper surface of the spacer using an adhesive (not shown). It is done. The spacer is chosen to be thick enough to provide clearance so that the overhanging edge of the upper die 454 does not impact the wire bond 446. The upper die 454 is electrically connected to the bottom substrate by a wire bond 456 connecting the wire bond site on a given trace 451 and the wire bond site on the functional surface of the die 454. The lower die 444, the upper die 454, and the wire bonds 446, 456 of the bottom package provide protection from ambient and mechanical stresses to facilitate processing operations and provide the top stacked die package 1000. Are encapsulated with a molding compound 917 that provides the upper surface of the bottom package that can be stacked. Solder balls 318 are reflowed over the connection pads on the metal layer on the underside of the substrate to provide interconnection with basic electrical circuitry such as, for example, the final product motherboard (not shown). Solder masks 455, 457 are patterned on metal layers 451, 453 to expose the underlying metal at the connection location for electrical connection. For example, the wire bond site and the bonding pad connect the wire bond and the solder ball 418.

  The top package 1000 is tested, stacked in a die attach area on the upper surface of the bottom package substrate, and attached using adhesive 1103. The electrical interconnection between the top package and the bottom package is made by connecting the wire bond site on the upper metal layer trace 451 of the bottom package substrate with the exposed wire bond site on the top package substrate trace 1011. Provided by wire bond 1118. The MPM assembly is then encapsulated with a mold 1107 to protect the wire bonds between packages and provide mechanical integrity in the finished MPM 110.

  An MPM having dies stacked in a top package or bottom package or both top and bottom packages can be particularly small upper surface space applications for large memory. The multi-package module of FIG. 11 may comprise, for example, a die memory top package stacked on top of a stacked ASIC bottom package. Alternatively, both the top package and the bottom package can be stacked dice memory packages that form a high density memory module.

  Other stacked die package configurations are used in accordance with this aspect of the invention for bottom or top stacked die packages in MPM, for example, depending on the number of stacked dies and the size of the stacked dies. obtain. For example, the stacked upper die of the bottom package has a smaller dimension than the lower die. In such a configuration, there is no protrusion of the upper die perimeter on the wire bond connection site at the edge of the lower die, and therefore it is not necessary to provide a spacer between adjacent adjacent dies. is there.

  Other top package configurations can be stacked on top of the stacked die bottom packages in accordance with this aspect of the invention. The BGA top package is stacked on top of the stacked die bottom package as illustrated in the configuration of FIG. 5A.

  As illustrated in FIG. 11, a heat spreader is provided on top of the top package for improved heat dissipation from a multi-package module having stacked die bottom packages. The top heat spreader is formed from a thermally conductive material that exposes at least a more central region of its upper surface to the surroundings for efficient heat exchange away from the MPM on the upper surface of the MPM. The top heat spreader is, for example, a metal plate (such as copper) that is attached to the MPM capsule during the molding material curing process. Alternatively, the heat spreader has a substantially planar portion on the top package and a peripheral support portion or support member disposed on or near the upper surface of the bottom package substrate.

  Not only MPM top MPM heat spreaders with stacked die bottom packages (or with stacked die bottom and top packages), but also top heat spreaders as illustrated by way of example in FIGS. 5D and 5E. Is appropriate.

  With respect to the MPM configuration of FIG. 11 and the heat spreader of FIG. 5E, for example, the top heat spreader includes a generally planar central portion 544 disposed over the top package and a peripheral support 546 extending to the upper surface of the bottom package substrate 442. Can be formed from a thermally conductive material. The upper surface of the planar portion 544 is exposed to the surroundings at the MPM upper surface for efficient heat exchange away from the MPM. The top heat spreader is formed from, for example, a metal plate (such as copper), and is formed by punching, for example. The support 546 can optionally be attached to the upper surface of the bottom package substrate using an adhesive. The configuration of the multi-package module is protected by the configuration of the module capsule body 1107, and the heat spreader support is enclosed in the MPM capsule body 1107 during the molding material curing process. Steps such as indentations 1045 can be applied to the outer periphery of the upper planar portion 1044 of the heat spreader to reduce layer cracking from the molding compound and provide more mechanical integrity for the structure. In this configuration, the space between the lower surface of the heat spreader 544 and the upper surface 1019 of the top package mold 1017 is filled with a thin layer of MPM mold.

  Alternatively, the top heat spreader can be attached to the upper surface of the top package mold. With respect to the configuration of the MPM of FIG. 11 and the heat spreader of FIG. 5D, for example, the top heat spreader 504 has at least a more central region of its upper surface exposed towards the surroundings for efficient heat exchange away from the MPM. It is a heat conductive substance that is almost flat. The top heat spreader is, for example, a metal plate (copper or the like). Here, however, the top heat spreader 504 is mounted on the upper surface 1019 of the upper package capsule body 1017 using an adhesive. The adhesive is a thermally conductive adhesive in order to provide improved heat dissipation. Typically, the top heat spreader is attached to the top package mold after the top package mold has been at least partially cured, but before the molding material is injected as the MPM capsule 1107. The periphery of the top heat spreader is encapsulated by MPM molding material. Steps such as recesses 505 can be applied to the outer periphery of the heat spreader 504 to reduce layer cracking from the molding compound and to obtain more mechanical integrity for the structure.

  As a further alternative, the MPM as in FIG. 11 does not have a support, i.e. does not attach to the upper surface of the top package mold, and can simply be provided with a planar heat spreader. In such a form, the top heat spreader can be substantially planar with a thermally conductive material such as a metal plate (such as copper). In addition, at least the more central region of the upper surface of the planar heat spreader is exposed to the periphery in order to perform efficient heat exchange away from the MPM. Here, the space between the lower surface of the simply planar heat spreader and the upper surface 1019 of the LGA mold 1017 is filled with a thin layer of MPM mold. Such simply planar heat spreaders are then attached to the MPM capsule body 1107 during the molding material curing process. The perimeter of such an unattached simply planar top heat spreader may be encapsulated by the MPM molding material, such as the attached planar heat spreader of FIG. 5D, and may be layered from the molding compound. Steps such as indentations 505 may be provided on the outer circumference to reduce the and obtain more mechanical integrity for the structure.

  As preferred by the above description, in all its various forms, the present invention features wire bond connection as a z-axis interconnection method between stacked packages. In general, all LGAs stacked on the lower BGA must be smaller (in at least one dimension of the xy plane) than the BGA to obtain wire bond space around it. The diameter of the wire is mainly on the order of 0.025 mm (range 0.050 to 0.010 mm). The length of the wire to the LGA substrate edge can vary in various forms, but is not shorter than the diameter of the wire. The relative size of BGA and LGA is determined primarily by the size of each largest die. The thickness of the die and the thickness of the mold cap are mainly determined by how many dies can be stacked in one package.

  The process of manufacturing BGA and LGA packages for use in the present invention is well established in both wire bond connection and package flip chip type industries.

  BGA testing is well established in the industry and is mainly done by making access contacts to solder ball pads. LGA can be tested in either of two ways. That is, it can be tested by approaching the LGA pads similar to the BGA solder ball pads on the lower surface of the LGA of the substrate, or by approaching the z-axis interconnect pads on the upper surface of the substrate. The completed MPM assembly can be tested in the same way as testing a BGA.

  The MPM assembly process is similar in construction according to various aspects of the present invention. In general, the process provides a first mold package comprising a first package substrate and at least one die attached to the first package substrate, and applying an adhesive to the upper surface of the first mold package. Placing a second mold package comprising a second package substrate and at least one die such that the lower surface of the second substrate contacts the adhesive on the upper surface of the first package during bonding. And forming a z-axis interconnect between the first and second substrates. Beneficially, the package can be tested prior to assembly, so that the first package and the second package are tested and determined to be “passed” for use in the assembly module. Packages that do not meet requirements or reliability can be disposed of.

  FIG. 12 is a flowchart showing a process of assembling a multi-package module as exemplified in FIG. 5A or 7. In step 1202, an undivided strip of ball grid array package is provided. The die and wire bond configuration of the ball grid array package is protected by the mold. The striped BGA packages are preferably tested for performance and reliability (indicated by * in the figure) before they enter the next process. Only packages that are certified as “passed” will undergo post-treatment. In step 1204, adhesive is applied to the upper surface of the mold over the “pass” BGA package. In step 1206, a singulated land grid array package is provided. The singulated LGA package is protected by a mold and is preferably tested (*) and certified as “pass”. In step 1208, a pick and place process is performed to place the “pass” LGA package on the adhesive on the mold of the “pass” BGA package. In step 1210, the adhesive is cured. In step 1212, a plasma clean process is performed as a preparation for step 1214. Then, at step 1214, a wire bond z-axis interconnect is formed between the stacked top LGA and bottom BGA packages. In step 1216, additional plasma clean is performed concomitant with the formation of the MPM mold in step 1218. In step 1220, secondary interconnect solder balls are attached to the underside of the module. In step 1222, the completed module is tested (*) and singulated from the strip, eg, by saw singulation or punch singulation, and packaged for further use.

  FIG. 13 is a flowchart showing a process of assembling a multi-package module as shown in FIG. 6A, for example. In step 1302, an unsingulated strip of ball grid array package is provided. The die and wire bond configuration of the ball grid array package is protected by a mold. The striped BGA packages are preferably tested for performance and reliability (as indicated by * in the figure) before they enter the next process. Only packages that are certified as “passed” will undergo post-treatment. In step 1304, an adhesive is applied over the upper surface of the mold of the “pass” BGA package. In step 1306, an individualized land grid array package is provided. The singulated LGA package is protected by a peripheral mold protecting the wire bond and is preferably tested (*) and certified as “pass”. In step 1308, a pick and place process is performed to place the “pass” LGA package on the adhesive on the mold of the “pass” BGA package. In step 1310, the adhesive is cured. In step 1312, a plasma clean process is performed as a preparation for step 1314. Then, at step 1314, a wire bond z-axis interconnect is formed between the stacked top LGA and bottom BGA packages. In step 1316, additional plasma clean is performed concomitant with the formation of the MPM mold in step 1318. In step 1320, a second level interconnect solder ball is attached to the underside of the module. In step 1322, the completed module is tested (*), eg, singulated from the strip by saw singulation or punch singulation and packaged for further use.

  FIG. 14A is a flowchart showing a process of assembling a multi-package module as shown in FIG. 8A, for example. In step 1402, an unsingulated strip of ball grid array package is provided. The BGA package includes a shield mounted on the die. The shield protects the die and wire bond configuration on the ball grid array package, and accordingly no package mold is required. The striped BGA packages are preferably tested for performance and reliability (indicated by * in the figure) before they enter the next process. Only packages that are certified as “passed” will undergo post-treatment. In step 1404, adhesive is applied over the shield upper surface of the “pass” BGA package. In step 1406, an individualized land grid array package is provided. The singulated LGA package is protected by a mold and is preferably tested (*) and certified as “pass”. In step 1408, the pick and place process is performed to place the “pass” LGA package on the adhesive on the shield of the “pass” BGA package. In step 1410, the adhesive is cured. In step 1412, the plasma clean process is performed as preparation for step 1414. Then, in step 1414, a wire bond z-axis interconnect is formed between the stacked top LGA and BGA packages. In step 1416, additional plasma clean is performed concomitant with the formation of the MPM mold in step 1418. In step 1420, a deflash process is performed to decompose and remove inappropriate basic elements. Deflash is performed by laser or by chemical or plasma clean. In step 1422, secondary interconnect solder balls are attached to the underside of the module. In step 1424, the completed module is tested (*), eg, singulated from the strip by saw singulation or punch singulation and packaged for further use.

  FIG. 14B is a flowchart showing a process of assembling a multi-package module as shown in FIG. 8B, for example. This process, like that shown in FIG. 14A, has the additional step of being inserted during heat spreader attachment by a “drop-in” mold process. Similar steps in the process are identified by similar reference numbers in the figures. In step 1402, an unsingulated strip of ball grid array package is provided. The BGA package includes a shield mounted on the die. The shield protects the die and wire bond configuration of the ball grid array package and correspondingly no package mold is required. The striped BGA packages are preferably tested for performance and reliability (as indicated by * in the figure) before they enter the next process. Only packages that are certified as “passed” will undergo post-treatment. In step 1404, adhesive is applied over the shield upper surface of the “pass” BGA package. In step 1406, an individualized land grid array package is provided. The singulated LGA package is protected by a mold and is preferably tested (*) and certified as “pass”. In step 1408, the pick and place process is performed to place the “pass” LGA package on the adhesive on the shield of the “pass” BGA package. In step 1410, the adhesive is cured. In step 1412, the plasma clean process is performed as preparation for step 1414. Then, in step 1414, a wire bond z-axis interconnect is formed between the stacked top LGA and bottom BGA packages. In step 1416, an additional plasma clean is performed. In step 1415, the heat spreader is dropped into each mold female mold by the female mold apparatus. In step 1417, the clean package stack from step 1416 is dropped into a mold mold on the heat spreader. In step 1419, the encapsulating material is poured into a mold female and cured to form an MPM mold. In step 1421, a deflash process is performed to decompose and remove inappropriate basic elements. Deflash is performed by laser or by chemical or plasma clean. In step 1422, secondary interconnect solder balls are attached to the underside of the module. In step 1424, the completed module is tested (*) and singulated from the strip, for example by saw singulation or punch singulation, and packaged for further use.

  FIG. 14C is a flowchart showing a process of assembling a multi-package module as shown in FIG. 8C, for example. This process is similar to that shown in FIG. 14A, with the additional step of being inserted during attachment of the planar heat spreader by attachment on the top package. Similar steps in the process are identified by similar reference signs in the figures. In step 1402, an unsingulated strip of ball grid array package is provided. The BGA package includes a shield mounted on the die. The shield protects the die and wire bond configuration of the ball grid array package and correspondingly no package mold is required. The striped BGA packages are preferably tested for performance and reliability (indicated by * in the figure) before they enter the next process. Only packages that are certified as “passed” will undergo post-treatment. In step 1404, adhesive is applied to the upper surface of the shield of the “pass” BGA package. In step 1406, an individualized land grid array package is provided. The singulated LGA package is protected by a mold and is preferably tested (*) and certified as “pass”. In step 1408, the pick and place process is performed to place the “pass” LGA package on the adhesive on the shield of the “pass” BGA package. In step 1410, the adhesive is cured. In step 1412, the plasma clean process is performed as preparation for step 1414. Then, in step 1414, a wire bond z-axis interconnect is formed between the stacked top LGA and bottom BGA packages. Thereafter, an additional plasma clean is performed. In step 1431, an adhesive is applied to the upper surface of the top LGA package mold, and in step 1433, a pick and place process is performed to place a planar heat spreader over the top package mold adhesive. Is done. In step 1435, the adhesive is cured. In step 1416, additional plasma clean is performed, and in step 1418, the MPM mold is formed. In step 1420, a deflash process is performed to decompose and remove inappropriate basic elements. Deflash is performed by laser or by chemical or plasma clean. In step 1422, second level interconnect solder balls are attached to the underside of the module. In step 1424, the completed module is tested (*) and singulated from the strip, for example by saw singulation or punch singulation, and packaged for further use.

  FIG. 15 is a flowchart showing a process of assembling a multi-package module as shown in FIG. 9A, for example. In step 1502, an undivided strip of downward facing die flip chip ball grid array bottom package is provided. BGA packages are supplied with or without a mold and are supplied with no secondary interconnect solder balls. Strip BGA packages are preferably tested for performance and reliability (indicated by * in the figure) before they enter the next process. Only packages that are certified as “passed” will undergo post-treatment. In step 1504, adhesive is applied to the upper surface (back side) of the die on the “pass” BGA package. In step 1506, a singulated land grid array package is provided. The singulated LGA package is protected by a mold and is preferably tested (*) and certified as “pass”. In step 1508, pick and place processing is performed to place the “pass” LGA package on the adhesive on the die of the “pass” BGA package. In step 1510, the adhesive is cured. In step 1512, plasma clean processing is performed as preparation for step 1514. Then, at step 1514, a wire bond z-axis interconnect is formed between the stacked top LGA and bottom BGA packages. In step 1516, additional plasma clean is performed in step 1518 concomitant with the formation of the MPM mold. In step 1520, secondary interconnect solder balls are attached to the underside of the module. In step 1522, the completed module is tested (*) and singulated from the strip, for example by saw singulation or punch singulation, and packaged for further use.

  FIG. 16 is a flowchart showing a process of assembling a multi-package module as shown in FIG. 9B, for example. This process is similar to that shown in FIG. 15, with the additional step of being inserted during the attachment of the shield over the bottom package flip chip die. Similar steps in the process are identified by similar reference signs in the figures. In step 1602, an undivided strip of downward die flip chip ball grid array bottom package is provided. BGA packages are supplied with or without a mold and are supplied with no secondary interconnect solder balls. The striped BGA packages are preferably tested for performance and reliability (indicated by * in the figure) before they enter the next process. Only packages that are certified as “passed” will undergo post-treatment. In step 1603, the electrical shielding material is mounted on a “pass” bottom BGA package die. In step 1604, adhesive is applied to the upper surface of the shield of the “pass” BGA package. In step 1606, a singulated land grid array package is provided. The singulated LGA package is protected by a mold and is preferably tested (*) and certified as “pass”. At step 1608, a pick and place process is performed to place the “pass” LGA package on the adhesive on the shield of the “pass” BGA package. In step 1610, the adhesive is cured. In step 1612, plasma clean processing is performed as preparation for step 1614. Then, in step 1614, a wire bond z-axis interconnect is formed between the stacked top LGA and bottom BGA packages. In step 1616, additional plasma clean is performed concomitant with the formation of the MPM mold in step 1618. In step 1620, a second level interconnect solder ball is attached to the underside of the module. In step 1622, the completed module is tested (*) and singulated from the strip, for example by saw singulation or punch singulation, and packaged for further use.

  FIG. 17 is a flowchart showing a process of assembling a multi-package module as shown in FIG. 10A or FIG. 10B, for example. In step 1702, an undivided strip of an upward die flip chip ball grid array package is provided. The flip chip interconnect is protected by an underfill or mold between the die and the die mounting surface of the bottom substrate. Thus, no extra mold is required. The striped BGA packages are preferably tested for performance and reliability (indicated by * in the figure) before they enter the next process. Only packages that are certified as “passed” will undergo post-treatment. In step 1704, adhesive is applied on the upper surface of the substrate of the “pass” BGA package. In step 1706, the separated second package is provided. It is a stacked die package as illustrated in FIGS. 10A and 10B. The diced second package is protected by a mold and is preferably tested (*) and certified as “pass”. In step 1708, pick and place processing is performed to place a “pass” second package on the adhesive on the substrate of the “pass” BGA package. In step 1710, the adhesive is cured. In step 1712, plasma clean processing is performed as preparation for step 1714. Then, in step 1714, a wire bond z-axis interconnect is formed between the stacked top (stacked dies) and the bottom upward die flip chip BGA package. In step 1716, additional plasma clean is performed concomitant with the formation of the MPM mold in step 1718. In step 1720, secondary interconnect solder balls are attached to the underside of the module. In step 1722, the completed module is tested (*) and singulated from the strip, for example by saw singulation or punch singulation, and packaged for further use.

  FIG. 18 is a flowchart showing the process of assembling a multi-package module as illustrated in FIG. In step 1802, undivided strips of stacked die ball grid array packages are provided. Stacked dice BGA packages are formed to supply the upper package surface. The striped BGA packages are preferably tested for performance and reliability (indicated by * in the figure) before they enter the next process. Only packages that are certified as “passed” will undergo post-treatment. In step 1804, adhesive is applied to the upper surface of the substrate of the “pass” stacked dice BGA package. In step 1806, the separated second package is supplied. That is a stacked die package as illustrated in FIG. The diced second package is protected by a mold and is preferably tested (*) and certified as “pass”. In step 1808, pick and place processing is performed to place a “pass” second package on the adhesive on the substrate of the “pass” BGA package. In step 1810, the adhesive is cured. In step 1812, a plasma clean process is performed as a preparation for step 1814. Then, in step 1814, a wire bond z-axis interconnect is formed between the stacked top (stacked dice) and the bottom upward die flip chip BGA package. In step 1816, additional plasma is performed concomitant with the formation of the MPM mold in step 1818. In step 1820, a second level interconnect solder ball is attached to the underside of the module. In step 1822, the completed module is tested (*) and singulated from the strip, eg, by saw singulation or punch singulation, and packaged for further use.

  Preferably, each of the various steps of the process according to the present invention uses substantially conventional techniques with direct modification of conventional assembly equipment such as the methods described so far. And can be performed according to the methods detailed above. Such variations between the prior art and the modifications required of conventional assembly equipment can be made using the previous description without undue experimentation.

  Other embodiments are possible within the scope of the claims.

50 Multi-package module, 400 Bottom package, 401 Edge, 412 Top package substrate, 413 Adhesive, 414 Dies, 415, 427 Solder mask, 416 Wire bond, 417 Molding compound, 418 Solder ball, 419 Bottom package upper surface, 421 , 423 metal layer, 422 bias, 424 bottom package z-axis interconnect pad, 426 capsule edge, 500 top package, 501 edge, 503,513 adhesive, 507 module capsule, 512 top package substrate, 514 dice 515,527 Solder mask, 516,518 Wire bond, 517 Molding compound, 519 Top package upper surface, 521,523 Gold Genus layer, 522 bias, 524 top package z-axis interconnect pad, 525 upper surface, 526 edge of capsule body.

Claims (2)

A multi-package module comprising a first and a second package stacked, wherein each of the first and second packages has a die attached to each of the first and second substrates, the first A multi-package module, wherein the first and second substrates are interconnected by wire bonding, and the first package comprises a flip chip ball grid array package having flip chips in an upward die configuration. Providing an upward facing die flip chip first package having a first package substrate;
Providing a second package having a die and a second package substrate, and stacking the second package on the first package;
A method of forming a multi-package module, wherein the first and second packages are electrically connected to each other by wire-bonding the first package substrate and the second package substrate.