Patent ID: 12243794

DETAILED DESCRIPTION

SiPs can enable integration of devices with diverse fabrication technologies such as digital, analog, memories, and other devices and components such as discrete circuits, devices, sensors, power management, and even other SiPs that are otherwise impossible or impractical to integrate in a single silicon circuit like an application-specific integrated circuit (ASIC) or SoC. These other discrete circuits may include non-silicon based circuits, such as organic, germanium, or Gallium Nitride (GaN) based circuits, as examples. SiPs are also attractive because SiPs can allow for miniaturization of microelectronic systems from a printed circuit board tens of square cm in size, to a single package often a few square cm or less. Another potential benefit of a SiP is that it can allow for building prototypes in order to test a system prior to further integration of some or all of components into a single monolithic silicon circuit.

SiP solutions combine multiple functional components and devices in a single package. Such SiPs may be either entirely customized for a specific function or purpose, or they may be general-purpose building blocks around which specific components may be added for a specific application. With general-purpose building block SiPs, they are often desirable because of the potential use in many applications with additional specific components added for each unique application. However, there may be drawbacks in both types of SiPs. For the case of custom SiPs, they are usually single-purpose products that require extensive redesign if there is a change to be made. A potential disadvantage of a general purpose SiP is that it grows the component count, and some of the space and costs savings of using a single purpose or custom SIP are lost. However, aspects of the present disclosure can overcome certain of these disadvantages.

For instance, and according to embodiments, a multi-step process allows portions of the SiP to be assembled as a standard sub-system of the final product. Other portions of the SiP substrate may be reserved for various additional components to be added at a later time and/or in a different physical business location such as, for example, but not limited to, a different assembly location, at an end customer's location, or a different city, state, or nation. The combination of the additional components with a general purpose SiP may be used to create a custom solution for a specific purpose. The final SiP may have different, or improved, functionality from the original functionality of the initial sub system. This may result, for instance, from the interconnection between the additional components and the original functional elements of the SiP.

According to embodiments, a SiP is provided that is customizable by a customer that, for example, only needs a small number of SiPs. The customer can acquire the SiPs with a standard sub-system already integrated into it. Once acquired, the customer can add special components unique to their product offering in the configuration area to create the exact product needed. The customer may do this for many reasons such as, but not limited to, unique applications, low volume applications, security or encryption and decryption circuits.

Aspects of the present disclosure allow customization of a packaged SiP without paying the penalty of additional price and design activity associated with fully custom SiPs. These secondary packaged components or devices may be designed by a user, and open up the use of general-purpose type SiP designs to limitless customization possibilities.

The terms “functional module” or “functional components” can be used to refer to one of a family of interchangeable substrates populated with components, or components or devices, for use in altering the function of a general purpose SiP device when electrically connected to a set of connectors associated with a general purpose SiP's base substrate.

According to embodiments, a general purpose SiP may be a customized SiP for a family of products with specific functionality. By way of example, the base SiP device may be altered to change its original functionality dependent on which packaged or unpackaged functional module from a family of modules is connected to a SiP's primary or base substrate. In the context of the current disclosure, an interposer may be used as another substrate in a SiP. The interior substrate may be the base substrate for the SiP or an interposer operatively connected inside the SiP. In some embodiments, a plurality of conductors may be arranged in a pattern on a bottom surface of the functional module for connecting to and mounting on a base substrate in a SiP. However the substrate on which the functional module or functional components is mounted may be the base substrate for the SiP, or an interposer inside the SiP.

Referring now toFIG.1, an example of System in Package (SiP) technology (also known as System on Module, Multi-chip Module, etc.) is illustrated. In this example, a system100can be created by integrating multiple components, both active (104,105,107) and passive (103,106) onto a substrate101. Once assembled, external connectors102are attached and the components encapsulated109to form a packaged semiconductor component. In the example ofFIG.1, the active components include a packaged device104, a semiconductor die105wire bonded108to the substrate, and a die using flip chip technology107to attach directly to the substrate. The passive components103and106may be capacitors, resistors, or inductors, for instance. Other components, not shown, may include, but are not limited to, diodes, transistors, optical devices, mechanical devices, and crystals. In this depiction, the external connectors102are conductive balls arrayed in a matrix, known as a ball grid array (BGA). These external connectors102may have leads or be leadless (not shown in this example).

Referring now toFIGS.2A,2B and2C, methods are illustrated according to some embodiments.

FIG.2Adepicts a manufacturing process200according to some embodiments. The process200may be used, for example, to attach a radio frequency (RF) connector210to a substrate of a base system in package (SiP) device. Although connector210is depicted as an RF connector in this example, other types of connectors or antennas can be used. For instance, connector210may be an optical connector for interfacing with one or more elements packaged within the SiP. Similarly, other types of devices may be used as element210, including SiPs.

The process200may begin by attaching201surface mounted devices (SMDs), such as devices103,104,106, onto the substrate. In step202, an integrated circuit in die form105is attached, and it connects to the substrate using bond wires108. Additionally, the RF connector210(or other component) is attached in step202. Next, a plug211is applied over the RF connector210in step203. This plug211will prevent encapsulant from filling the space occupied by the plug. The plug211may be, for example, a removable filler or a cap like cover. Other plugs may be used. Next, the substrate is encapsulated in step204. In this depiction, the encapsulant covers the whole surface including the plug211. Once encapsulated, a portion of the encapsulant over the plug211is removed at step205(e.g., shaved or ground off) to expose the plug211. According to embodiments, the entire substrate is encapsulated (204), followed by the entire upper surface being shaved or ground (205), not just the region of the plug. In step206, the plug is removed. This may be performed at a later time and/or location. The plug removal exposes the RF connector (or other device mounted in that location). Following satisfactory testing, for instance, the SiP is available for use. Examples of testing may include, for example, testing of an RF or optical component within the partially encapsulated base SiP where the connector210will be used as an antenna or other connection. Other examples of testing may include, for example, confirming that the partially encapsulated components are correctly configured using a USB or Ethernet connection210.

FIG.2Bdepicts another manufacturing process220according to some embodiments. As with process200, process220may be used, for example, to attach an RF connector210to a substrate of a base SiP device. Although connector210is depicted as an RF connector in this example, other types of connectors or antennas can be used. In process220, the plug is used to preserve an opening in the encapsulant for subsequent attachment of the connector (or other component, such as a circuit). In some embodiments, the additional component may be one or more of additional memory devices, wireless or wire-lined communications circuitry, security circuitry, Field Programmable Gate Arrays (FPGAs), Field Programmable Analog Arrays (FPAAs), sensors, video and analog interface devices.

According to embodiments, the process220begins with step201by attaching surface mounted devices103,104,106(SMDs) onto the substrate. The next step221attaches a plug211to the area designated for the RF connector (or other component) to keep mold compound out of that area. That is, a plug211may be applied before mounting of the additional component (e.g., component210), or at any time during the assembly process prior to encapsulation. In step221, the die105may also be mounted and connected to the substrate using bond wires (e.g.,108). While depicted as a single step, the application of the plug and mounting of components need not be performed in a single processing step. According to embodiments, the plug will prevent any encapsulant from filling the space designated for the RF connector. The entire substrate is then encapsulated at step224. In this example, the encapsulant covers the whole surface including the plug. Once encapsulated, the encapsulant is partially removed225(e.g., shaved or ground off) in the area over the plug to expose the plug211. In step226, which may be optional, the plug is removed to expose the (surface mount) SMT space on the SiP substrate for RF connector210, and the RF connector can subsequently be installed on the substrate. In step227, the RF connector is shown as installed. Following satisfactory testing, the SiP with the installed RF connector is available for use. Alternatively, a device as shown at step224or225may be shipped to a customer, using the plug211to seal and protect the mounting area.

FIG.2Cdepicts a manufacturing process240according to embodiments, which can be used to attach a separate component (e.g. a functional module or functional components)243, after a primary SIP assembly has been completed.

The process240may begin (like step201) by attaching surface mounted devices103,104,106(SMDs) onto the substrate. The next step241comprises attaching a plug to keep mold compound out of the area designated for a secondary component (e.g. a functional module or functional components). This plug (e.g., plug211) will prevent the encapsulant from filling the space designated for the secondary component (e.g. a functional module or functional components). In step244of this example, the encapsulant covers the whole surface including the plug. Once encapsulated, in step245the encapsulant is partially removed (e.g., shaved or ground off) in the area over the plug to expose the plug. In step246, the plug is removed to expose the SMT space for the secondary component (e.g. a functional module or functional components). In step247, the secondary component243is shown as installed. In step248, the whole assembly may then be re-encapsulated, as illustrated. That is, according to embodiments, the process240may comprise two encapsulation steps.

According to embodiments, the plug may be, for example, but not limited to, a printed three-dimensional plug that may be hollow or solid, or any other type of three-dimensional plug. The plug may be constructed of any suitable material that will withstand molten encapsulant, and may be suitably attached to the substrate, such as for example, but not limited to solder and a solder mask outlining the area to be protected from the encapsulant. Further, the profile for the plug may be in any geometrical shape, such as triangular, circular, square, rectangular, etc.

As the time or place of steps245,246,247, or248may be delayed or relocated to another assembly facility in another building, city, state or country according to embodiments, a SiP may be stored or transported in any of the conditions shown. For example, it could be stored or shipped after the initial encapsulation244, after the removal of the package surface, either before (245) or after (246) the removal of the plug. It could also be stored or shipped after the circuit(s)243have been added, either prior to247or after the second encapsulation of the SiP248.

According to embodiments, a packaged SIP is provided that comprising a substrate comprising a plurality of layers with etched conductive paths, a plurality of vias associated therewith for making component interconnections, and one or more connectors in a preselected area on a top surface of the substrate for mounting at least one additional device or component and for making additional interconnections for the at least one additional device or component; a plurality of components are mounted on the substrate and operatively interconnected using the vias and conductive paths; and encapsulant covers and protects the plurality of components are mounted on the substrate; and wherein the preselected area of the substrate is not encapsulated and is configured for operatively connecting at least one additional device or component and for making a plurality of connections to the substrate using the one or more connectors on the preselected area of the top surface of the substrate. There may be more than one such preselected area on the top surface of the substrate.

FIGS.3A,3B,3C,3D and3Edepict examples of SiPs. Such SiPs may result from the methods ofFIGS.2A-2C(200,220,240).

Referring now toFIG.3A, a SiP300is illustrated according to embodiments that has an RF connector310(or other connector or device) attached to the SiP substrate and exposed so that the mating connecter (not shown) may be connected to it. Other components304,305,306on the substrate301are encapsulated303to protect them. External connectors302are attached to the substrate301to complete the SiP. Although connector310is depicted as an RF connector in this and other examples, other types of connectors or antennas can be used. For instance, connector310may be an optical connector for interfacing with one or more elements packaged within the SiP. Similarly, other types of devices may be used as element310, including SiPs. According to embodiments, SiP300may correspond to one or more of processing steps and devices206and227.

FIG.3Bdepicts an alternative version320according to embodiments, which may correspond to processing step and device246. In this SiP configuration320, a portion of the substrate321is exposed with various substrate surface connectors330ready for secondary components to be attached. The other components on the substrate (324,325,326) are encapsulated323to protect them. Finally, external connectors322are provided on the substrate321.

Referring now toFIG.3C, a fully packaged SiP340is illustrated. In this example, a component350is attached to an exposed area of the substrate341. Once the component350is attached, the SiP may be encapsulated a second time with encapsulant351to protect the new component(s)350, in addition to the already encapsulated components344,345,346, which are covered by the first encapsulant343. In some embodiments, rather than a second full encapsulation351, the non-encapsulated area may be filled with other protective materials.

FIG.3Dillustrates a sectional view of the partial encapsulation361of a SiP360, with a portion364of the substrate362exposed. This portion364may have a predetermined set of conductive pads365on which additional components may be added to modify the functionality of the SiP360. For instance, a device mounted in region364may modify or otherwise augment the functionality of a set of components within encapsulant261. Once the additional components have been added, the SiP may be encapsulated a second time, covered with an appropriate material, or left exposed. This may be, for instance, as illustrated with respect to encapsulant351ofFIG.3C.

FIG.3Eillustrates a sectional view of the partial encapsulation381of a SiP380, with two exposed portions384and386of the substrate382. Although two such areas are depicted in this example, multiple such portions may be crated according to embodiments. The two portions of exposed substrate384and386may have a predetermined set of conductive pads385on which additional components387may be added to modify or otherwise augment the functionality of the SiP380, or on which an external connector (e.g., an optical connection) may be added. Once the components (e.g.,387) have been added, either, or both may be encapsulated as illustrated with respect toFIG.3C, for example, or they may be otherwise covered with an appropriate material, or left exposed, any one of which may be determined by the end use of the SiP. According to embodiments, the exposed portions of the substrate may be on any or all of the four corners or four sides of the substrate. In certain aspects, non-square substrates, devices, and exposed portions may be used.

FIGS.4A,4B,4C and4Ddepict methods for developing SiPs according to embodiments. The methods can provide, for instance, SiP substrates that have a permanent portion and at least one configurable portion.FIG.2may indicate one or more steps related to these methods.

FIG.4Ashows a method400of the first step of a process according to embodiments.FIG.4Amay be, for instance, a method for creating SiP ready customization. It begins by populating401the SiP substrate with the permanent set of components. Once the permanent set of components are attached, a plug is attached402to the substrate on the areas that will be left un-encapsulated (or bare) after the encapsulant has been added403. After the encapsulant has been added, the top surface of the encapsulant is removed404such that the plug is exposed. Finally, after acceptable testing405, the encapsulated SiP is put in inventory ready for the addition of the configurable portion of the components.

FIG.4Bshows a method420for manufacturing a complete SiP product. According to embodiments, it begins with populating421the SiP substrate with the permanent set of components. A second step may comprise attaching422the plug to the substrate. According to embodiments, the plug may be attached at any time during the assembly process prior to encapsulation. Next, the first encapsulation423is performed. At this time, an intermediate production test429may be performed to determine if the SiP is ready for the next assembly step. A next step may be removing part of the encapsulant424to expose the plug. In some embodiments, this step may be delayed until the appropriate time for the configurable components to be attached. This may provide, for instance, protection for the mounting surfaces until such time. Once the top surface of the encapsulant over the plug is removed and the plug exposed, the plug is removed at step425. With the plug removed, a configurable set of components may be attached426to the SiP substrate (e.g., a functional module or other component may be attached). In some embodiments, individual components may be attached to adjust the SiP configuration. In some embodiments, a set of components on a substrate may be attached via the other substrate to adjust the SiP configuration. For instance, the functional module may itself be a SiP. A second encapsulation427of the SiP may then be performed to cover the whole SiP. According to embodiments, materials other than encapsulant may be used to protect the installed configurable set of components. Finally the completed SiP is tested428. Following satisfactory testing, the SiP is available for use.

FIG.4Cshows a method440that comprises multiple parts.FIG.4Cmay be, for instance, a method for creating end product at a vendor and/or customer. According to embodiments, a SiP may be created in an assembly house in the first set of steps, for example, according to steps441-445. These steps may comprise populating the SiP substrate, attaching the plug, applying a first encapsulant, and shaving the encapsulant to expose the plug. According to embodiments, the SiP is then shipped446to a customer or its assembly site. Additionally, steps of removing the plug447, populating448the exposed substrate with the configurable components, and encapsulating449the whole SiP may then be performed. According to embodiments, the method440may conclude with performing a production test450. According to embodiments, the second encapsulation may be customized by the customer to meet their environmental, quality, reliability, or security requirements. In some embodiments, the first encapsulant may be a molding compound, like a thermoplastic or thermosetting resin. In some embodiments, the second encapsulant may be a polymer/epoxy coating or glue, which is different from the first. In certain aspects, the second encapsulant may be selected to prevent removal or alteration of the functional module.

FIG.4Ddepicts a variation of a process460that ends with an exposed area on the SiP, including secondary components.FIG.4Dmay be, for instance, a method for adding exposed components on a SiP according to embodiments. In certain aspects, steps461through466are the same as steps421-426. However, and according to embodiments, the second encapsulation may be skipped such that the secondary configuration components are left exposed. This method may be useful for attaching, for example, but not limited to, connectors, sensors, displays or switches to the SiP. Once completely assembled the SiP is tested467in some embodiments.

Referring now toFIG.5, a process500is provided according to embodiments. The process500may be used, for instance, to manufacture a SiP as illustrated in connection withFIGS.2and3, for instance.

The process may begin with step510, in which a base substrate having a first portion and a second portion is provided. Providing the base substrate510could include, for instance, manufacturing, sending, receiving, or otherwise obtaining the base. In step520, a plurality of components are formed on the first portion of the base substrate, where the plurality of components define a first functionality for the SiP. Forming520may include, for instance, mounting and/or interconnecting the components such that they perform a desired function. In step530, a plug is installed on the second portion of the base substrate, where the second portion of the base substrate is separate from the first portion of the base substrate. In step540, the plurality of components formed on the first portion of the base substrate and the plug installed on the second portion of the base substrate are encapsulated. In step550, at least a portion of the encapsulant located over the plug is removed. For instance, it may be shaved away to expose the plug. In steps560and570, which may be optional in some embodiments, the plug is removed and then one or more additional components are interconnected in the location of the plug. The additional components may be, for instance, a circuit, antenna, Ethernet connector, USB connector, or optical connector. The entire package may be encapsulated (e.g., with a second, different encapsulant), to form a fully packaged SiP (not depicted).

In some embodiments, the additional components change the first set of functionality to a second set of functionality, or add a second set of functionality to the first set of functionality. For example, the first set of functionality may comprise one or more of general purpose processing, transmit/receive functions, sensing functions, analog or digital or mixed signal functions, and optical processing/switching, while the second set of functionality is one or more of security, encryption, communications, sensing, transmission/receive functions.

In some embodiments, one or more additional components are interconnected with the base substrate in the second region before the plug is installed. According to embodiments, the plug is installed over the additional components.

While various embodiments of the present disclosure are described herein, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present disclosure should not be limited by any of the herein above-described exemplary embodiments. Moreover, any combination of the herein above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context. Accordingly, other embodiments, variations, and improvements not described herein are not excluded from the scope of the present disclosure. Such variations include but are not limited to new substrate material, different kinds of devices attached to the substrate not discussed, or new packaging concepts.

Additionally, while the processes described above and illustrated in the drawings are shown as a sequence of steps, this was done solely for the sake of illustration. Accordingly, it is contemplated that some steps may be added, some steps may be omitted, the order of the steps may be re-arranged, and some steps may be performed in parallel.