Techniques for ovenized device fabrication

Abstract

An ovenized system having a hot region (having heat structures and / or circuitry heated to a set point temperature) and a cold region (structures, electrical paths or circuitry not heated to the set point temperature, as well as ambient) utilizes a thermally-engineered interposer and, optionally, atmospheric control to regulate heat flow from the hot region according to respective heat flow paths. The disclosed techniques provide for low power, more efficiently produced ovenized systems, and methods for designing and making those systems. In some embodiments, the interposer can also be structured to inhibit coupling of external mechanical vibrations, leading to greater system ruggedness and reliability.

Description

TECHNIQUES FOR OVENIZED DEVICE FABRICATIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This disclosure claims priority to each of the following U. S. Provisional Patent Applications: (1) US Patent Application No. 63 / 728678, which was filed for " Integrated Circuit Package" on 5 December 2024 on behalf of first-named inventor Markus Rudolf LUTZ; (2) US Patent Application No. 63 / 867061, which was filed for " Integrated Circuit Package" on 20 August 2025 on behalf of first-named inventor Markus Rudolf LUTZ; (3) US Patent Application No. 63 / 893553, which was filed for " Integrated Circuit Package" on 3 October 2025 on behalf of first-named inventor James Howard Thomas RANSLEY; (4) US Patent Application No. 63 / 916442, which was filed for " Ovenized Oscillator" on 12 November 2025 on behalf of first-named inventor James Howard Thomas RANSLEY; and (5) US Patent Application No. 63 / 917980, which was filed for " Ovenized Oscillator Designs" on 14 November 2025 on behalf of first-named inventor James Howard Thomas RANSLEY. Each aforementioned patent application is hereby incorporated by reference, as is US Patent Publication No.20250011162 (USSN 18712420 filed under 35 USC §371 on 22 May 2024 by first-named inventor Nicholas MILLER).BACKGROUND

[0002] Certain types of electronic systems rely on an "ovenized" or "oven-controlled" environment, in which certain structures and / or circuitry are heated to a predetermined "set -point" temperature, and in which is typically desired to maintain thermal isolation from an ambient environment and / or other structures or circuits.

[0003] For example, some systems are dependent, for proper operation, on temperature-invariant operation of certain circuitry or structural components. To avoid or to minimize temperature-dependent variation inherent in the design of these components, one well-known class of designs features an "ovenized" region, in which these sensitive components are heated to, and maintained at, a predetermined "set point" temperature, which is usually well above an expected operating temperature range (e.g., above a range of -40 degrees Celsius (°C) to +95°C, or another specified range). Typically, not all components of the system are heated to this range, i.e., the larger the heated area (and the more structures and / or circuits are heated), the longer it takes the part to reach the set point temperature, and the more difficult it becomes to precisely regulate the set point temperature. Consequently, many systems typically feature a defined "hot region" withSpecification, SA1097-PCT / 2025027thermal isolation to minimize heat loss to other parts of the system, which are not temperature-regulated (although these other parts or regions are collectively referred to as the "cold region," i.e., it should be understood this term is used to cover any region which is not to be heated to and maintained at the set point temperature). As processing and logic circuitry typically does not suffer from significant temperaturedependent variation, these system elements typically reside in the cold region. One or more signals produced by "hot region" circuitry or structures are typically fed through thermal insulation to "cold region" system components. Recent designs implement the entire system of interest as a packaged integrated circuit device (e.g., having one or more chips and, optionally, a mounting frame, routing, encapsulation and electrical contact pads or pins).

[0004] However, it can be challenging to produce an effective design and / or reliable product. Because semiconductor materials are usually used to make these systems as integrated circuit devices, atmospheric and / or constituent materials can provide a path for substantial heat loss, leading to power-hungry designs and substantial challenges in sensing current temperature in the hot region, and heating the hot region to the set point temperature and in efficiently maintaining that temperature. Attempts to isolate "hot" and "cold" regions can also complicate device manufacture and lead to reliability issues.

[0005] What are needed are improved ovenized systems and techniques for creating those systems. Ideally, such techniques would provide for systems that can be reliably implemented as packaged integrated circuit devices and provide ultra-low-power designs. The present invention satisfies these needs and provides further, related advantages.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a diagrammatic view showing features and advantages associated with using an interposer in an ovenized system, according to the techniques provided by this disclosure.

[0007] FIGS. 2A-2D are illustrative views of exemplary interposer configurations in an ovenized electrical system: in FIG. 2A, an interposer is mounted as an element that thermally links structures and circuitry in standalone hot and cold regions; in FIG. 2B, hot region structures and circuits are directly mounted on an interposer, with the interposer providing a physical structure that electrically and thermally couples to standalone cold region circuitry; in FIG. 2C, a temperature-sensitive component and, optionally, other circuitry, are standalone components, and an interposer mounts other circuitry which can be either hot region or coldSpecification, SA1097-PCT / 2025027region circuitry, depending on embodiment; in FIG. 2D, an interposer 209d mounts both hot and cold region components, thermally linking them together, and structurally mounting them relative to other elements of a packaged integrated circuit device.

[0008] FIG. 3A is a side view showing one embodiment of a packaged integrated circuit device that implements an ovenized system.

[0009] FIG. 3B is a schematic view, used to discuss high-level design perspectives associated with the embodiment of FIG. 3A.

[0010] FIG. 3C is a plan view of an interposer having a hot circuit die 355 mounted atop the interposer; trenches, slots and or a serpentine or labyrinthic structural path, in combination with a suitable atmospheric context, facilitates close-quarter separation of hot and cold circuit components.

[0011] FIG. 3D is a plan view of another interposer having a hot circuit die 375 mounted thereon; here, a complex slot pattern and / or a serpentine or labyrinthic structural path, in combination with a suitable atmospheric context, not only provides thermal isolation, but also permits the interposer to function as a phononic crystal, inhibiting the coupling of structural vibrations at frequencies defined as a function of the various pathway widths, bends and constituent materials of the interposer (i.e., which form a phononic crystal unit cell).

[0012] FIG. 4A is a block diagram showing one embodiment of a packaged integrated circuit device; as indicated in the FIG., optionally, this packaged integrated circuit device can take the form of an oven-controlled oscillator (" OCXO").

[0013] FIG. 4B is a block diagram showing an OCXO, in this case, one based on a dual-MEMS design with additional downstream electronic (e.g., PLL-based) frequency correction, thus forming a temperature-compensated, oven-controlled oscillator (" TCOCXO"). The embodiment of FIG. 4B represents a programmable design, i.e., where a frequency of the output oscillation signal can be varied according to a programmable value.

[0014] FIGS. 5A-5F show a number of different options and configurations for a packaged integrated circuit device; most if not all of the depicted features can be mixed and matched in various permutations and combinations. FIGS. 5A, 5B, 5C, 5D, 5E and 5F each show respective, different examples of a packaged integrated circuit device that implements an ovenized system.Specification, SA1097-PCT / 2025027

[0015] FIG. 6A is a side view showing another embodiment of a packaged integrated circuit device which implements an ovenized system; more particularly, FIG. 6A illustrates use of a three-dimensional interposer having a first, block portion, which structurally supports hot region structures and circuitry, and a second, electronic bridge portion 605, which is attached separately from the first, block portion, to provide for electrical interconnection between hot and cold structures and circuitry.

[0016] FIG. 6B is a side view showing yet another embodiment of a packaged integrated circuit device which implements an ovenized system; notably, the embodiment of FIG. 6B separates hot region and cold region circuitry into respective cavities or chambers.

[0017] FIG. 7A shows a heat flow model that can be used in assessing performance of an ovenized system.

[0018] FIG. 7B shows another heat flow model that can be used in assessing performance of an ovenized system.

[0019] FIGS. 7C-7H each show graphs associated with design of an ovenized system based on the resistive network model seen in FIG. 7B. More specifically: FIG. 7C shows a plot of power consumption versus temperature expected for each of atmosphere (gas), interposer (glass) and conductors (WB) heat flow paths, achievable using techniques introduced by this disclosure; FIG. 7D shows a plot of effective thermal resistance versus temperature for each of these three heat flow paths, achievable using techniques introduced by this disclosure; FIG. 7E shows a plot of thermal conductance versus temperature for of these three heat flow paths, achievable using techniques introduced by this disclosure; FIG. 7F shows a plot of total power versus hot region heat flow in an exemplary design; FIG.7G shows a plot of hot region heat flow as a function of thermal resistance in an exemplary design; and FIG. 7H shows a plot of total power versus thermal resistance in an exemplary design.

[0020] FIG. 8A is a table showing the thermal conductivity of different atmospheric gases.

[0021] FIG. 8B is a table showing power consumption / leakage, sorted by atmosphere, interposer (glass) and conductor (wire bonds) in one ovenized system design, at a temperature of +20°C.

[0022] FIG. 8C is a table showing power consumption / leakage, sorted by atmosphere, interposer (glass) and conductor (wire bonds) in one ovenized system design, at a temperature of -40°C.

[0023] FIG. 9 is an illustrative diagram, used to discuss design of an interposer to inhibit coupling of external vibrational coupling to hot region structures (e.g., a resonator 904).Specification, SA1097-PCT / 2025027

[0024] FIG. 10A is a depiction of one embodiment where an interposer is structured to inhibit vibrational coupling to hot region structures and / or circuits.

[0025] FIG. 10B is a side view of another embodiment where an interposer inhibits vibrational coupling to hot region structures and / or circuits.

[0026] FIG. 10C is a side view of yet another embodiment where an interposer inhibits vibrational coupling to hot region structures and / or circuits.

[0027] FIG. 11 is a graph, used to discuss how an effective spring constant provided by an interposer's design can affect vibrational coupling.

[0028] FIGS. 12A-D illustrate techniques for the fabrication of an interposer and its integration into a system or device. More particularly, FIG. 12A illustrates an interposer material bonded to an underlying substrate or carrier. FIG. 12B shows the additional deposition of metal layer atop the interposer material, and associated further patterning of this metal layer. FIG. 12C shows the singulation of multiple interposers from a common array, in a manner facilitating ensuing package assembly; in FIG. 12C, circuitry (e.g., hot or cold region circuitry, as conceptually represented by presence of a dashed-line IC) can optionally be mounted to the interposer before or after singulation. FIG. 12D further shows these singulated products, but with the underlying substrate and / or carrier now removed.

[0029] FIGS. 13A-E illustrate techniques for the fabrication of an interposer and its integration into a system or device. More particularly, FIG. 13A illustrates an interposer material bonded to an underlying substrate or carrier, but with masking added to facilitate the cutting of slots or trenches into the interposer material (and, e.g., the formation of serpentine or labyrinthic routing in a heat flow path, as illustrated in FIG.3D). FIG. 13B shows the same structure as seen in FIG.3A, but with slots or trenches now etched in (i.e., material removed from) the interposer material. FIG. 13C shows the further formation of a patterned metal layer atop the assembly of FIG. 13B. FIG. 13D shows the optional mounting of circuitry (e.g., a hot or cold region integrated circuit) in a bulk-arrayed format. FIG. 13E shows the singulation of multiple interposers from a common array, in a manner facilitating ensuing package assembly.

[0030] FIGS. 14A-C illustrate techniques for the fabrication of an interposerand its integration into a system or device. More particularly, FIG. 14A illustrates an interposer material layer as having been bonded to an underlying substrate or carrier, but with vias and bottom level electrical contacts already formed. As seen in FIG. 14B, metal patterning can be added to the top layer and trenches / slots can be added (e.g., using the processSpecification, SA1097-PCT / 2025027of FIGS. 13A-E); the array can then be singulated, as seen with optional mounting of circuitry (e.g., hot or cold region integrated circuit) on each singulated interposer. FIG. 14C further shows these singulated products, but with the underlying substrate and / or carrier now removed.

[0031] FIGS. 15A-H illustrate one technique for the fabrication of an interposer and its integration into a system or device. More particularly, FIG. 15A shows a flex printed circuit board (PCB) mounted atop a rigid, patterned PCB. FIG. 15B shows this same assembly but with presence of surface conductors added to provide electrical contact with vias, and with underlying tooling to support the flex PCB; die stacks for hot region components have now been added and wire-bonded to each other and to the surface conductors, and the hot region components have now been optionally encapsulated, as graphically depicted. In FIG. 15C, the tooling has been removed and singulated products have now been added atop a carrier (i.e., atop the shaded block at the bottom of the FIG.); in FIG. 15D, this singulation has been carried over to the carrier, leading to several assemblies. FIG. 15E shows the patterning of a glass panel or a flat ceramic substrate base with cold circuitry ICs now bonded to it (i.e., via depicted solder ball connections) and with material for contacts now added to the base. FIG. 15F shows the singulation of the base of FIG. 15E, with a corresponding chip stack from FIG. 15E now added, and with hot and cold regions of an ovenized system thereby connected together. Finally, FIG. 15G shows the bonding of a cover / lid over each singulated product and the bulk completion of an array of integrated circuit devices.

[0032] FIG. 16 is a flow chart showing an assembly method featuring a prefabricated interposer module.

[0033] The subject matter defined by the enumerated claims may be better understood by referring to the following detailed description, which should be read in conjunction with the accompanying drawings. This description of one or more particular embodiments, set out below to enable one to build and use various implementations of the technology set forth by the claims, is not intended to limit the enumerated claims, but to exemplify their application. Without limiting the foregoing, this disclosure provides several different examples of techniques for building systems having ovenized structural or electrical components including, without limitation, temperature-stable timing signal generators. These techniques can be embodied as improved "ovenized" system designs, as manufacturing and / or assembly techniques for ovenized system designs, as techniques for fabricating thermal components of an ovenized system (e.g., an interposer, with or without pre-mounted structures, circuitry or electrical paths), or in some other manner. While specific examples are presented, the principles described herein may also be applied to other methods, devices and systems as well.Specification, SA1097-PCT / 2025027DETAILED DESCRIPTIONI. Introduction.

[0034] In one embodiment, one or more interposers embodying techniques provided by this disclosure are mounted within an ovenized system, thereby facilitating low-power devices and more precise sensing and / or regulation of set point temperature; the use of these interposers can also facilitate device assembly processes. Generally speaking, an interposer can be manufactured as a planar panel or three-dimensional support block, structured so as to provide tailored levels of thermal isolation. Some designs also feature structures that inhibit vibrational coupling, thereby providing for much greater device resistance to shock. It should therefore be appreciated that the techniques provided by this disclosure substantially enhance the capabilities, cost, and usability of ovenized systems, and the ease of design of those systems.

[0035] More specific embodiments provide for controlled thermal regulation of one or more primary heat transfer paths from the "hot region" of an ovenized system, and by separately engineering each path; for a given atmospheric thermal resistance, for example, a component of heat flow from the hot region can be channeled through an interposer device, which is engineered to have specific thermal characteristics. In some embodiments, electrical paths are optionally routed through the interposer device, with some (or all) of these electrical paths designed (e.g., routed, sized) so to assist with thermal regulation; in some embodiments, these paths can be embedded at least in part in or on a support substrate, or they can be routed through a separate element (i.e., a modular element physically mounted in the system so as to form part of an interposer device). In this regard, some designs discussed below also use a controlled atmosphere (e.g., an oven chamber atmosphere having a low-thermal-conductance gas and / or a partial vacuum) in order to reduce atmospheric heat transfer, and to thereby provide increased control over the thermal design of remaining heat transfer paths, especially through non-electrically-conductive materials of the interposer and through electrical conductors. Optionally, the design of these latter two paths can be routed so as to route heat flow to a substrate area for cold region circuitry, and from there to thermal contacts, package boundaries and an external ambient atmosphere. In many but not all embodiments, the ovenized system is an oscillator, a gyroscope, an accelerometer, a pressure sensor or some other type of sensor, optionally based on a quartz crystal resonator or some other type of resonator; in other embodiments, the ovenized system can optionally feature one or more microelectromechanical systems (" MEMS") structures of some type, i.e., each with an element or structure that moves, deflects or vibrates.

[0036] In this regard, as noted earlier, proper regulation of heat flow from a hot region of a system can present significant challenges; these challenges can include the need to balance thermal isolation (increased Specification, SA1097-PCT / 2025027thermal isolation reduces power consumption) against self-heating from the circuits used to run the particular sensor or other system type. In this regard, it should be understood that the hot region of an ovenized system typically includes (a) structures or circuitry to be maintained at the set point temperature, (b) a heating element (i.e., selectively controlled to drive the hot region toward the set point temperature) and (c) a temperature sensor (i.e., to sense contemporaneous temperature in the hot region); the heating element is typically controlled through feedback, such that the set point temperature is exactly reached and not exceeded (i.e., at least within a small threshold). However, if the thermal insulation provided in a given design is "too" good, a problem can be created in that power used to drive hot region structures or circuitry can result in a large temperature increase of the circuitry, leading to overshoot of the set point temperature and exit from the control loop (i.e., as a typical system has no means to actively cool the circuitry); the nature of this problem can change depending on the ambient environment (i.e., because the minimum thermal exit changes for a given thermal resistance as a function of an varying difference between the set point temperature and the ambient temperature). An example of this problem would be helpful: in an oven-controlled oscillator (" OCXO") system, a hot region typically includes a resonator of some type and sustain circuitry, which powers, drives, or otherwise adjusts resonator performance; most resonators typically have some degree of temperature-dependent variation in resonant frequency, and the sustain circuitry is typically expected to cause the resonator to reliably operate throughout an entire rated temperature range of interest, e.g., -40°C to +95°C. In such an environment, the hot region of the ovenized system might therefore be designed to always maintain the hot region components (e.g., resonator and sustain circuitry) at a set point temperature well above the -40°C to +95°C range, for example, at +115°C, to render irrelevant the inherent temperature-dependent variation of the resonator. However, if thermal isolation is "too good," it is possible if the system is not properly designed that, even with the heating element turned "off," the power used to drive the sustain circuitry might heat the hot region to temperatures well above the set point temperature (e.g., >115°C); this becomes increasingly likely when the ambient operating temperature of the system is close to the high end of the rated range (e.g., >+90°C in this example) and when the system is very well thermally isolated - such that relatively small power dissipation in the hot region results in a large temperature increase of that region. For proper operation throughout the desired operating range, therefore, the ovenized system should be designed to have at least some maximum thermal resistance (measured in degrees Kelvin per Watt, or " K / W"), such that the power generated by the essential circuits operating in the hot region (measured in Watts, W, or milliWatts, mW) causes at most a limited temperature rise (measured in°K) - enabling the circuitry to operate at all temperatures of interest. Further, the system's thermal resistance can be limited so that the power consumption is bounded at cold ambient temperatures (i.e., such that the heating element can be as sparingly used as possible). [Note that the concept of thermal leakage, as discussed herein, will also be expressed in the form of thermal Specification, SA1097-PCT / 2025027conductivity or the inverse of thermal resistance (e.g., a low thermal resistance means that there is greater thermal leakage).] As these statements imply, it is desired in some designs to minimize power consumed by the ovenized system (a principal component of which is oven heating to the set point temperature); the thermal resistance can be advantageously designed so that the inherent heat generated by operation of hot region structures and circuits comes close to maintaining a desired set point temperature, with as little additional heat from the heating element as is needed; the interposer, atmosphere and / or related structures provided by this disclosure can be designed with these constraints in mind, to provide customized hot region heat leakage and / or exit regulation. In some embodiments, overall thermal flow from a hot region is restricted to a range of 1000 kelvins-per-watt (K / W) to 5000 K / W, and in other embodiments, other ranges can be produced, e.g., 2600 K / W to 3000 K / W. These design constraints lead to exceedingly low-power ovenized systems. In other embodiments, each heat flow path can be individually engineered, for example, by designing thermal resistance to be no less than 1000 K / W for each of atmospheric, electrical conductor, and non-electrical interposer heat flow paths. Other design parameters and associated design ranges are also outlined herein.

[0037] One embodiment of the techniques introduced by this disclosure therefore takes the form of two or three dimensional interposers, i.e., modular heat-flow structures, which can be installed / mounted in ovenized systems to provide thermal coupling between hot and cold regions. These interposers can be designed to provide a tailored range of thermal resistance and heat flow (also termed heat leakage in this application). For example, one non-limiting embodiment discussed below implements an interposer as a cantilevered substrate, where hot region components are mounted in a controlled atmosphere; the controlled atmosphere can be designed to greatly reduce atmospheric heat loss, providing for greater regulation over total heat transfer through engineering of the interposer itself (and, optionally, through engineering of electrical conductors). In such an embodiment, hot region structures and / or circuits can optionally be mounted directly on the interposer (e.g., structured in a manner akin to a very-high-insulation "circuit board"), with the hot region portion of the interposer and hot region components surrounded on four or more sides by a controlled atmosphere. In some embodiments, the atmosphere used is a partial vacuum and / or has an especially-low-thermal-conductance gas (e.g., a Noble gas), with suitable minimum gap spacings from any adjacent cavity surface. As a result, in some embodiments, heat loss through the surrounding atmosphere can be regulated to be less than 0.001 watts-per-degree-Kelvin (W / K) and, in other cases, to less than 0.0002 W / K. At the same time, the effect of this isolation is to channel heat flow from the hot region through conductors and the cantilevered substrate; one or both of these elements can be engineered to provide a range of heat flow where the minimum depends upon the minimum required heat flow path, e.g., according to the constraints discussed above. Note that the use of these design techniques permit both hot region and cold region components to optionally be housed in one and theSpecification, SA1097-PCT / 2025027same general chamber, that is, with the 'hot region' being adjacent the cold region and separated seemingly only by atmosphere (e.g., and a shared structural support); thus, contrary to conventional wisdom, in many embodiments, the use of a controlled atmosphere with suitable gap spacings - and a suitable interposer -provides sufficient thermal isolation between hot and cold regions, while still providing for an thermally efficient, low-power design.

[0038] In one embodiment, an interposer can take the form of a substantially planar panel, e.g., as a high-thermal resistance support structure for one or more components a hot region of an ovenized system (or indeed, in one embodiment, all of those components); for example, the interposer can be made to be a thin glass, ceramic or polymeric panel. Optionally but advantageously, such an interposer can play a part in a manufacturing process which pre-mounts hot region components to the interposer, such that an assembly of hot region components and interposer are then attached as a modular element in a packaged integrated circuit device or other system; it should be noted that this is not required for all embodiments and, further, that alternate interposer designs can be configured to mount cold region components, both hot region and cold region components, or none of these components at all, depending on implementation.

[0039] The interposer in one embodiment is advantageously designed to have a material that provides at least a minimum amount of thermal resistance, typically including one or more materials that each provide a structural thermal resistance of no less than about 1000 K / W. In the case of non-electrically-conductive portions of the interposer, this can be achieved using one or more suitably thick layers of low-thermal-conductance material, such as a glass, a polymer or a ceramic material. Optionally, the interposer can be deliberately patterned and / or dimensioned to assist in this effort, for example, having a labyrinthic path such that a long thermal path length can be routed in a relatively short space, with path turns or folds routed using a minimum gap distance within a controlled atmosphere. In some further embodiments, the interposer can be bundled with electronic connections or pathways that can be structured (e.g., in terms conductor diameter, material type, or other parameters) to also present higher-thermal resistance than conventional electrical routing (e.g., with a thermal resistance of no less than about 1000 K / W). Optionally also, these electrical connections can directly abut or be embedded in the layer of high thermal resistance materials (e.g., within or upon a glass, a polymer or a ceramic), such that the respective heat flow paths can be well understood for purposes of design and modeling.

[0040] In still more detailed embodiments, the interposer can also be engineered so as to also inhibit vibration coupling, helping make an ovenized system mechanically robust to shock and / or vibration caused by the operation of other system components (e.g., certain types of capacitors or other electrical or mechanical Specification, SA1097-PCT / 2025027devices). This can be achieved either by engineering an interposer (e.g., in terms of material thickness and flexibility) to function as one or more support springs, or alternatively, designing a "labyrinthic" interposer support structure which effectively functions as a phononic cell.

[0041] Another embodiment of the techniques introduced herein is an ovenized system based on one or more of the teachings introduced above. One implementation is an ovenized system employed as a oscillator, gyroscope, accelerometer, pressure sensor, another type of sensor, or some other type of system. In contemplated optional implementations, an entire ovenized system can be formed as a packaged integrated circuit device having one or more dies, with an interposer thermally-coupling these dies. For example, one contemplated implementation is an oven-controlled oscillator (" OCXO") package having a first die and a second die; the first die can present as hot region circuitry and can include or be supplemented by a heating element and / or temperature sensor, and the second die can present as cold region circuitry that is electrically coupled to the hot region circuitry. Such a packaged integrated circuit device can feature external electrical pins which are used to output an oscillation signal for use by downstream, external devices. In one embodiment, a multifunction interface can be used to support two-way communications over a single external pin, contact or signal line of the packaged integrated circuit device (e.g., a common, binary serial signal can be used for two-way transfer various types of information, including to receive programming of a desired output oscillator signal frequency). For implementations which provide an OCXO, it is noted that the techniques herein can be applied to systems featuring any type of resonator, including without limitation, a quartz crystal resonator and / or a microelectromechanical systems (" MEMS") resonator. Some designs will use multiple resonators, e.g., a dual-MEMS design which combines both ovenization to minimize temperature-dependent variation and also generates a temperature signal (based on divergence of, or a ratio between, the MEMS resonators' frequencies). Still more detailed embodiments can provide for further fine tuning of residual frequency error in an output oscillation signal, e.g., with electronic correction provided within cold region circuitry (such as a PLL) based on the temperature signal (this type of oscillator device would then be a temperature-compensated, oven-controlled oscillator, or a " TCOCXO"). Many other optional variations, applications and implementations will be discussed below and / or are discussed in the priority documents.

[0042] Still another embodiment provides a manufacturing method, whether or not used to produce systems and / or devices introduced above. As part of such a method, one or more hot region elements or circuits and / or one or more cold region elements or circuits can be physically mounted on an interposer, or an interposer can be installed to thermally couple those elements. The interposer can optionally be a modular element which supports prefabricated electrical routing which will electrically-couple the hot region structures and / or circuits with the cold region structures and / or circuits. The interposer can be mounted on a first Specification, SA1097-PCT / 2025027structure (e.g., a base, frame, or other system support) and a second structure can then be mounted to the first structure, so as to enclose the interposer, hot region components and cold region components; this enclosure then creates a cavity or chamber which will contain the hot region components (and possibly some or all of a set of cold circuitry as well). In some embodiments, there is additional partitioning within the cavity or chamber between hot region and cold region components, while in other embodiments, the various hot and cold circuitry elements can share a common cavity and / or atmosphere. In still other embodiments, some of these steps can be varied or changed, e.g., with an interposer being mounted first and respective hot region and cold region elements attached thereto, or with a separate assemblies being mounted to the interposer (e.g., an electrical coupling device), with the aggregate of multiple assemblies fulfilling the role of interposer. Still another embodiment provides for a method of manufacturing an interposer.

[0043] Additional embodiments will be apparent from the discussion that follows. The use of these various techniques, in any permutation, facilitates low power designs of ovenized devices (including without limitation, integrated circuit devices). In addition, these techniques facilitate device manufacture processes and improve device reliability; as these statements imply, none of these features should be considered "essential" for any given embodiment or application.

[0044] Prior to proceeding to this additional description, it would be helpful to first discuss some specific terms. Firstly, it should be understood that contemplated embodiments can include "hardware logic," "circuits" or "circuitry" (each meaning one or more electronic circuits). Generally speaking, and unless otherwise specified, these terms can include analog and / or digital circuitry, and can be, in nature, special purpose or general purpose. For example, as used herein, the term "circuitry" for performing a particular function can include one or more electronic circuits that are either "hard-wired" or are configurable circuits to perform the stated function (i.e., in some cases without assistance of instructional logic), and the term can include a microcontroller, microprocessor, FPGA or other form of processor which is general in design but which runs software or firmware (e.g., instructional logic) that causes or configures general circuitry (e.g., configures or directs a circuit processor) to perform the particular function. Note that as these statements imply, "circuits" and "circuitry" for one purpose are not necessarily mutually-exclusive to "circuits" or "circuitry" for another purpose, e.g., such terms indicate that one or more circuits are configured to perform a function, and one, two, or even all circuits can be shared with "circuitry" to perform another function (indeed, such is often the case where the "circuitry" includes a processor); this is to say, "circuitry to perform (function X)" and "circuitry to perform (function Y)" can encompass exactly the same circuitry or respective circuits, depending on implementation. Related to these points, the term "logic" can encompass hardware logic, instructional logic, or both, unless otherwise specified. Instructional logic can be code written or designed in a manner that has certain Specification, SA1097-PCT / 2025027structure (architectural features) such that, when the code is ultimately executed, the code causes the one or more general purpose machines (e.g., a processor, computer or other machine) each to behave as a special purpose machine, having structure that performs, upon occurrence of defined events, described tasks with respect to processing operands, or else take specific actions or produce specific outputs. Generally speaking, some of the circuits and / or processes described herein can, in some embodiments, be implemented as instructional logic (e.g., as instructions stored on non-transitory machine-readable media or other software logic), as hardware logic, or as any combination or permutation of these things, depending on embodiment or specific design. In connection with various embodiments herein, the term "device" is used to refer to an electronic product (e.g., based in, but not limited to, a chip, system, or board) with circuitry and possibly, but not necessarily, resident software or firmware. A "packaged" device typically refers to a device which is configured as a single integrated circuit device and which may have, for example, one or more dies or chips (e.g., electrically interconnected), with molding or encapsulation if desired, and with suitable pins or pads for electrical mounting and / or connection with the outside world. The term "integrated circuit" (or " IC") typically refers to a structure having at least one die, packaged or otherwise, and, as implied, a single IC and / or die can also be a type of electronic device. A "packaged integrated circuit device" can include one or more discrete components or chips which are commonly mounted, for example, in the form of a stack or other structure, enclosed, encapsulated or otherwise, with contact pins or pads for electrical coupling with the outside world. The term " MEMS" refers to electromechanical structures that are used at and / or operate at the circuit board, die, IC or similar level, regardless of whether such are characterizes as "miniature," "micro," "nano," or otherwise in terms of scale. " Substrate" and / or "chassis" as used herein refers to a structure that physically supports or mounts electronical routing, circuitry or some type of vibrating, deflecting or moving element - for example, this term can include a wafer, a die, a lead frame, silicon offsets or pillars, a ceramic support, an IC or some other structure; typically herein, the term "substrate" will be used to describe a relatively flat (e.g., planar) structure having one or more layers and the term "chassis" will be used in a broader sense to encompass two-dimensional or three-dimensional support structures (e.g., including, but not limited to, a substrate). " Divider" and "multiplier," unless otherwise specifically indicated, are used herein in a manner that is synonymous, e.g., to refer to frequency increase and / or reduction of an oscillating signal by any one of a number of structures in a feedback path of a PLL loop, whether integer-based, fractional, programmable or otherwise. The term " PLL" should be taken, unless expressly indicated to the contrary, to generally encompass any locked-loop structure used for timing control, including by way of example, delay-locked loops and other structures, and unless otherwise indicated, can take forms of digital or analog structures, irrespective of whether specific conventional circuit structures (e.g., XOR gate as a phase detector) are used. The terms " PLL" and " PLL loop" and "locked-loop circuit" will generally be used in this disclosure as synonyms. " Non-transitory," to the extent used herein, Specification, SA1097-PCT / 2025027refers to any tangible (i.e., physical structure) medium or mediums, irrespective of the type of technology used to express data on that medium and irrespective of the format of data storage; for example, in one case, a particular expression can be optically stored on physical media and, in another case, the particular expression can be magnetically stored on physical media. Thus, when applied to storage and / or computer-readable and / or machine-readable subject matter, the term "non-transitory" indicates that data and / or instructions can be stored on such a physical structure storage medium using optical, magnetic, electronic, resistive and / or other storage formats / technologies. " Instructions" can be implemented in different formats, depending on embodiment; for example, as code written in a specific programming language (e.g., as C++ code), as a processor-specific instruction set, or in some other form. A "controlled atmosphere" as used herein refers to an environment atmosphere that is set or regulated in some manner that differentiates it in terms of pressure or chemical composition from ambient air (e.g., outside of an electronic device), e.g., this term can encompass a full or partial vacuum, and / or the use, presence and / or absence of one or more specific gases in a manner that differentiates it from ambient air; for example, in some embodiments discussed herein, a "controlled atmosphere" will include an atmosphere having a strong presence of a low-thermal-conductance Noble gas, such as xenon, argon or krypton, optionally also at a low pressure that effectuates a partial vacuum. " Module" or "modular" is used herein to mean a structure or collection of structures dedicated to a specific function; for example, a "first module" to perform a first specific function and a "second module" to perform a second specific function, when used in the context of instructions (e.g., computer code), refer to mutually-exclusive code sets. When used in the context of mechanical or electromechanical structures (e.g., an "interposer module") the term "module" refers to a dedicated set of components which might include physical structures and / or electronic circuits; in all cases, the term "module" is used to refer to a specific structure for performing a function or operation that would be understood by one of ordinary skill in the art to which the subject matter pertains as a conventional structure used in the specific art (e.g., a modular assembly), and not as a generic placeholder, "nonce" or "means" for "any structure whatsoever" (e.g., "a team of oxen") for performing a recited function (e.g., "for generating an electronic oscillation signal"). In the subsequent text, reference is sometimes made to conductive and / or non-conductive bonded connections. " Non-conductive" bonded connections are typically used to mechanically attach a die that is to be wire bonded to another entity (such as a die, interposer, base etc.) and these typically include die attach (dispensed, printed via inkjet or applied as a die attach film) and pressure sensitive adhesives / adhesive tapes. In the context of this disclosure wire bonded dies can also be mechanically bonded using an electrically-conductive die attach (such as an epoxy with appropriate conducting filler) provided that there is only one electrical connection to the body of the die via the bonding that is held at fixed potential or grounded. " Conductive bonded connections" are mechanical connections that include electrical connections (e.g., including flip-chip bonding, e.g., using solder, with or without underfill, and with or Specification, SA1097-PCT / 2025027without compression), thermosonic bonding (e.g., using gold), eutectic bonding, hybrid bonding, transient liquid phase (TLP) bonding and similar technologies; for example, other "conductive bonded connections" include the use of anisotropic conducing film or anisotropic conducing adhesive applied to a die's underside. It is within the level of ordinary skill in the art to determine which of these techniques is applicable for the specific embodiment and the specific individual connections at issue.

[0045] The meaning of other terms used herein should be clear based on context. Note that, to the extent that any document is incorporated herein by reference, the definitions of this document should be taken to predominate over any inconsistent definitions provided by such incorporated-by-reference documents. It is again emphasized that the various elements discussed above or below, in any embodiment, can be used in any desired permutation or combination, in the same or in any other embodiment, with all such permutations and combinations being expressly contemplated by this disclosure. Selection and / or omission of structures for any given design or application is within the level of ordinary skill in the art, and none of the elements / structures discussed herein are to be deemed "essential" for any purpose or function.II. Interposer Configurations In An Ovenized System.

[0046] FIG. 1 is an illustrative diagram used to explain some features associated with use of an interposer in one embodiment. These features are generally referenced by numeral 101, with textual recitations within functional block 103 indicating context for use of the interposer. More particularly, in an electronic systems' context, it is assumed that a component is characterized by a temperature-dependent operation or behavior; in order to minimize variation in one or more component characteristics (i.e., as a function of variation in localized operating temperature), that component is placed in an ovenized environment, that is, an environment that is maintained exactly at (or within a small threshold about) a "set point temperature." In other words, the effect of temperature-dependent behavior of the component is mitigated by never allowing the temperature to vary in the first place. Note that because ambient temperature can vary, and because many (if not most) electronic products are expected to have a rated range throughout which accurate device operation is desired, the set point temperature is typically engineered to be outside, and somewhat higher than, the desired rated temperature range of the product. For example, the expected operating temperature range can be a standard range for rated operation of an electrical system, such as between 0 degrees Celsius ("°C") and +70°C, between -40°C and +85°C, between -55°C and +125°C (or between some other temperature range), with the set point temperature being chosen to be a value higher than the associated range, e.g., +85°C in the case of an range of -0°C and +70°C, +115°C in the case of an range of -40°C and +95°C, and so forth; these values are illustrative. A relatively-high set point temperature permits accommadation of ambient temperatures Specification, SA1097-PCT / 2025027throughout the ambient rated range, as well as allows for some extra heating as a function of the power consumed by hot region components as headroom within the set point temperature. As this description implies, ovenized systems typically include, in addition to a temperature-sensitive structure or circuitry, each of a temperature sensor, some type of heating element, and some type of control circuit, with feedback being used to exactly arrive at and maintain the set point temperature. In a specific class of applications contemplated by this disclosure, the temperature-sensitive structure or circuitry can feature a resonator that is relied upon to generate a temperature-invariant timing signal (e.g., the ovenized system can be an oscillator); other contemplated applications include, without limitation, various types of sensors, such as gyroscopes, accelerometers, pressure sensors and other types of systems. As also indicated by block 103, an ovenized system also often includes low-temperature circuitry and / or structures; this should be understood to include any components that are not to be heated to the set point temperature, including without limitation components at ambient temperature or that will operate at a temperature in between the set point temperature and ambient temperature. In this regard, it is typically desired to consume as little power as possible and, to this end, the hot region of the ovenized system is therefore kept as small and as contained as is feasible, with circuitry and / or components that are not required to be temperature-invariant advantageously placed in the low temperature region. In the context of an oscillator implementation, processing circuitry (e.g., such as a PLL, heater control logic, output drivers, memory, and logic used for other functions) is typically positioned in this low temperature region (i.e., within the "cold" region).

[0047] As indicated by numeral 105, an interposer is engineered / specifically designed in this embodiment to thermally-couple hot region structures / circuitry with cold region circuitry, and to provide, allow and / or regulate a specific range of heat flow. When used in combination with a low-thermal conductance atmospheric environment, per block 107, this combination facilitates designs where hot and cold region components can positioned in relatively close proximity within the same enclosed chamber, i.e., defying conventional wisdom. Note that block 107 has a dashed-line box which indicates for this and subsequent blocks that the corresponding feature is optional. This is to say, the atmosphere in one embodiment can be chosen such that atmospheric heat leakage from the hot region is regulated, and such that remaining heat leakage from the hot region is channeled substantially through the interposer and / or conductors; the interposer in this event is engineered to provide minimal thermal flow at all rated temperatures while at the same time providing sufficient isolation such that the heating element used to ovenize the hot region of the system can be used as sparingly as possible. In some embodiments, as referenced by numeral 109, the interposer can be configured as a substantially flat panel or substrate, installed as a modular element in a device (e.g., within the system and / or packaged integrated circuit under manufacture) while, in other embodiments, the interposer can be three-dimensionalSpecification, SA1097-PCT / 2025027structure (e.g., it can take the form of a block, patterned or otherwise). As referenced by numeral 110, the interposer can optionally be configured to feature a serpentine or labyrinthic structure so as to permit relatively close proximity of hot and cold regions within the system (e.g., see the exemplary plan views of labyrinthic and / or serpentine configurations which are presented in FIGS. 3C and 3D).

[0048] As noted earlier, electrical paths that couple hot and cold region components also can be a source of thermal leakage from hot region components, all the more since electrically-conductive materials are also usually thermally conductive. To facilitate overall system design and manufacturing efficiency, electrical pathways between hot and cold regions can also be combined with an interposer design, and these paths too can be engineered or structured to regulate thermal leakage, i.e., by customizing one or more of conductor diameter, path length, constituent materials and / or other parameters; for example, as represented by numeral 111 in FIG. 1, electrical paths coupling hot and cold regions can optionally be routed for at least a portion of their paths through the interposer. The mounting of the interposer as a modular system element during device assembly can thus also be used to facilitate electrical interconnection, with thermal and electrical paths being coupled at the same time and / or at the same time through the same structural pathway, as non-electrical thermal coupling. In one embodiment, per numeral 111, electrical paths can be buried for at least a portion of their length in the interposer material, with all sides of that path encapsulated by one or more low-thermal conductance materials; this phraseology should be understood to encompass conductors can be configured as surface traces (e.g., which are "sandwiched" between a low-thermal-conductance interposer material and a low-thermal-conductance controlled atmosphere). Per numeral 113, it is also theoretically possible to design interposer-resident conductors out of somewhat higher thermal-resistance materials (e.g., specific metal alloys comprising manganese) to assist with thermal flow regulation via the electrical conductors - in addition to, or instead of, configuring path and path length of those electrical conductors so as to impart a desired thermal resistance. In embodiments referenced by numerals 117 and 119, either of (or both of) hot and cold region circuitry can be pre-mounted to the interposer, e.g., as respective ICs which are separated by the interposer for heat flow purposes; this optional pre-mounting, as referenced above, also facilities installation of electronics on a modular basis, thereby facilitating the manufacturing process (e.g., the device assembly process); in each case, the interposer acts as a regulated heat flow "bridge" between hot and cold regions, facilitating thermal engineering of the ovenized system at issue.

[0049] Per numeral 123, the ovenized system can, dependent on application, be built to be an oscillator, an accelerometer, a gyroscope, a pressure sensor, some other type of sensor, or another type of system. For applications where an ovenized system includes a resonator, a quartz crystal can optionally be used; in other embodiments, a resonator can take the form of a microelectromechanical systems (" MEMS") resonator, an LC Specification, SA1097-PCT / 2025027resonator, or some other type of resonator. In one optional design, the ovenized system can take the form of a dual-MEMS oscillator IC, e.g., where two MEMS resonators having different temperature-versus-frequency characteristics are used within the hot region, where these resonators are operated side-by-side and at the same temperature (i.e., the set point temperature), and where deviation in their respective resonant frequencies is used to precisely sense temperature at a high-resolution; a resultant temperature signal can be used to regulate control of the heating element to maintain the set point temperature, as well as (optionally) to inject fine electronic correction in an oscillation signal in processing circuitry, i.e., as to be completely temperature-invariant. For example, in such a system, one of these resonators can be engineered / designed to be a temperature-flat resonator (i.e., with an oscillation signal being generated based on its output); frequency variation as a function of very slight temperature variation can be learned during a post-assembly characterization / calibration step, with resultant-correction factors programmed into cold-region circuitry and used, during run-time, to provide PLL-based fine-tuning correction of an output oscillation signal.

[0050] FIGS. 2A-2D are used to illustrate various high-level interposer assembly options in an ovenized system. More specifically, FIG. 2A shows the integration of an interposer module in an ovenized system in a manner that links standalone hot and cold region components. FIG. 2B shows a different interposer configuration, namely, one that directly mounts hot region structures or circuits on an interposer module; that is, the interposer module can optionally be assembled with the depicted hot region elements first, and then the entire assembly can be installed in a system or package as a prefabricated modular unit, e.g., by bonding the interposer to contact pads and / or by otherwise structurally and electrically mounting the interposer, as conceptually represented by mount icon 211b. FIG. 2C shows yet another interposer design, this time where an interposer directly mounts some circuitry, but not necessarily all hot region structures or components (e.g., as represented by the separate depiction 232, the interposer in this embodiment need not mount one or more temperature variant structures, such as a MEMS device). FIG. 2D, by contrast, illustrates a configuration where an interposer directly mounts both hot and cold region elements, including respective ICs 203 / 233; once again, an aggregate structure having circuitry can optionally be assembled as a pre-fabricated modular element, and then fitted into a cavity or otherwise assembled into a package or system. In each case, the interposer is structured so as to provide thermal isolation between hot and cold region components (i.e., including the ambient environment outside the package or system). In each of these FIGS, an interposer is represented as a shaded block, and modular connections are represented by a mount icon e.g., 211a, 211b, etc.

[0051] Elaborating, FIG. 2A shows a first embodiment 201 in which a system features a modular interposer 209a. Thie FIG. also shows other standalone structures in the system, including hot region components 203 (e.g., including, as seen, a temperature sensitive component, a heater of some type and a heat sensor), cold Specification, SA1097-PCT / 2025027region circuitry 207, a common cavity or chamber 205, and package exterior electrical contacts 209. Each of the depicted elements can be added before or after the interposer, depending on embodiment, but in the embodiment of this FIG., the interposer is mounted as a modular element, via mount / pads 211a and 211b, so as to form the thermal and electrical connection between the hot and cold region structures and elements. As with many of the other embodiments discussed herein, the atmosphere within the depicted cavity or chamber 205 is structured in terms of structural gaps and / or atmospheric makeup, so as to minimize heat flow through the atmosphere and so as to channel a sizeable portion of overall heat flow through the interposer 209a, with interposer material and dimensions and the paths of electrical conductors designed so as to provide tailored ranges of thermal resistivity (and therefore heat flow from the hot region). In some embodiments, as referenced by a dashed-line demarcation 206, the depicted cavity or chamber optionally can be split into two separate cavities (e.g., see the example provided by FIG. 6B, discussed below).

[0052] FIG. 2B shows a second embodiment 221, with elements similar to those introduced with respect to FIG. 2A having like-numbering. In this FIG., however, an interposer 209b is seen to directly mount the hot region circuitry 203. For example, the hot region circuitry may optionally reside on a dedicated IC or a stack of hot region ICs (as appropriate to the specific design) which are pre-mounted to the interposer 209b, e.g., using solder mounts (or other bonded conductive connections), wire bonds, or some other bonded conductive and / or non-conductive connection or die attach). In some embodiments, an adhesive tape or conductive underfill can also be used to structurally support and thermally link the hot region structures and circuits to a "hot side" of the interposer. The structure of the interposer then serves to regulate a substantial portion of overall thermal flow from the hot region, with heat flow then being conveyed to a "cold side" of the interposer, and from there, through a device enclosure to the ambient environment. In the depicted embodiment, supporting cold region circuitry 207 can be independently mounted or it can be connected to the system as a standalone and / or separately-mounted component.

[0053] FIG. 2C represents yet another embodiment 231, with an interposer 209c in this case directly mounting only certain circuitry 233 (which may be either hot or cold region circuitry), in a manner where thermal isolation is provided within the interposer itself, i.e., between various mounted circuits represented by functional block 233. As depicted by the separate presence of temperature-sensitive components 232, a "hot side" mounting 211a of the interposer couples to a hot-side support structure in the system (or directly to a temperature sensitive / hot region component 232), while a cold side mounting, downstream from high-thermal-resistance elements, is used to mechanically and thermally connect the interposer assembly with a package, chassis, enclosure, or other part of the system.Specification, SA1097-PCT / 2025027

[0054] Finally, FIG. 2D shows an embodiment 241 in which an interposer directly mounts both hot and cold region components (i.e., including a temperature sensitive component, heater and heat sensor 203, and supporting hot and cold circuitry 233). In this case, once again, the interposer provides thermal isolation between hot and cold system components, with a cold side mounting 211b coupling the interposer assembly to ambient through a package, chassis, enclosure, etc. Once again, the depicted interposer can optionally be preassembled with one or more of the depicted circuit elements and then installed during device assembly as a modular element; alternatively, the depicted elements can be assembled in some other order (e.g., the interposer can be physically mounted first, followed by structural mounting of and / or electrical mounting of the depicted hot and / or cold region structures and elements). Many manufacturing configurations and variations will naturally occur to those having ordinary skill in the art.III. Trade Offs Between Interposer Configurations And Atmospheric Thermal Leakage.

[0055] FIG. 3A shows another example of a system implementation 301, where an integrated circuit package is seen (in a side view) to include a base 303 and a lid 305, with a cavity 307 defined between these two structures. More specifically, the depicted assembly can be assumed for present to represent a MEMS-resonator-based ovenized system, configured as an OCXO, though of course other applications are possible. In the depicted FIG., a hot region 309 contains a "hot circuitry" die 315 as well as a MEMS die 317. The MEMS die 317 has one or more MEMS structures, for example, one, two, or a larger number of MEMS resonators and, in this embodiment, is adhered to a top of the hot circuitry die using an adhesive mount of some type 319b, for example, a thermally-conductive underfill; in the FIG., electrical connections 321a are established between the two dies separate from the mechanical mount, i.e., using wire bonds 321a. This die stack can be prefabricated, if desired. In the depicted system, the entire die stack (317 / 319b / 315) will be locally-heated to the set point temperature; although not separately depicted in this FIG., an associated heating element can be positioned anywhere nearby or in these dies. In the depicted case, for example, the heating element should be assumed to be a part of (and inside) the hot circuitry die 317, near its top surface, such that the thermally conductive underfill between dies directly couples (e.g., "thermally shorts") heat from the heating element to the MEMS resonators in the MEMS die. Dashed-line 309 therefore represents the hot region of the system in this embodiment. The hot region elements (e.g., die stack 315 / 317) are, in turn mounted to an interposer 313 having some or all of the characteristics referenced above. In the depicted case, the interposer features top surface pads or mounts 329, which are wirebonded (321b) to the "hot circuitry" IC or die 317; optionally, the hot circuitry die in this embodiment can also be physically supported on the interposer 313 by an adhesive tape and / or thermally-conductive adhesive, represented by reference numeral 319b. Electrical signals to or from wire bonds 321 are electrically conveyed via the interposer (and more specifically via depicted conductive path Specification, SA1097-PCT / 2025027connections 333) to circuitry in the cold region or cold side of the depicted system, in this case, to circuitry and / or structures within the dashed-line box 311. The cold region is seen to include one or more cold circuitry dies (e.g., 323); additionally, the cold region includes thermal connections to a package base 303, to various mounts physical offsets or other support structures 333, 335 and 337, to walls of the packaged integrated circuit device, and so forth. These thermal connections provide a heat flow path from the interposer and cold circuitry to the ambient environment. As with previously-discussed examples, heat flow from the hot region of the system is regulated by the interposer 313 (and, more specifically in this example, by a configuration of a heat path within at least a "throat region" 335 of the interposer 313). The depicted cold circuitry die 323 can be wirebonded to the interposer, via pad(s) 331, such that electrical signals coming from or destined for the hot region couple to conductive paths 333, and from there to the respective hot region structures and circuits; in turn electrical connections to the outside world (e.g., to exterior pins or pads 339 of the packaged IC) can be routed from the cold region circuitry, via wire bonds 327, or alternatively, can be coupled directly through the interposer to physical offsets 335 and to the base 303, for coupling to exterior pins or pads 339. As was the case with the individual ICs 315, 317 and 323, the interposer in this embodiment can be bonded or adhesively mounted to offset / support 335, for example, via an adhesive or other type of mount 333.

[0056] It was earlier commented that the design of the interposer 313, in combination with an atmosphere 308 inside the cavity or chamber, advantageously permits independent engineering of a structural component of thermal leakage, via design of the interposer 313, so as to provide a tailored range of structural heat flow. There are a number of design options that can be used to facilitate this goal, some of which are as follows: First, as alluded to earlier, in one embodiment, the interposer can be fabricated to include a high-thermal-resistance material, for example, at least one of a glass, a polymer, or a ceramic, or some other thermally-resistive material. In one embodiment the entire interposer can be made as a unitary block or panel of this material while, in other contemplated embodiments, the interposer can feature a layer stack; for example, one or more layers can be formed from a high-thermal-resistance material, optionally on top of another material. Optionally also, high thermal conductance materials can be in a specific area, such as in a throat region (335) which thermally-couples hot and cold sides of the interposer. As noted earlier, these techniques can also optionally be combined with the use of slots, trenches, serpentine or labyrinthic patterns in the interposer's physical structure, so as to further attain necessary path length, in view of the thermal resistance of the particular materials used, to thereby establish a desired thermal resistance and / or implement mechanical vibration resistance (e.g., a phononic crystal unit cell). In one embodiment, conductors 333 are buried within the high-thermal resistance materials, while in other embodiments, the conductors 333 are instead formed as surface traces (e.g., atop a top, high-thermal-resistance material layer, sandwiched between the high-thermal-resistance materials of theSpecification, SA1097-PCT / 2025027interposer and a high-thermal-resistance controlled atmosphere). In still other embodiments, the interposer, though depicted in this FIG. as a unitary device, can instead feature multiple components; for example, conductors 333 can be formed on a separate chip or structure and being wirebonded to each of pad(s) 329 and 331, with this separate wire bonding step and separate chip or structure used to electrically couple those structures. Finally, as noted already, the interposer can be designed to implement one or more minimum thermal resistances, for example, no less than 1000 K / W (aggregate), or with electrically conductive paths having no less than a target thermal resistance (e.g., 1000 K / W) and with non-electrically-conductive structures having no less than a target thermal resistance (e.g., 1000 K / W). Nearly any range or metric can be specified, depending on design, with different embodiments satisfying minimum thermal resistances for different heat flow component paths of 400 K / W, 800 K / W, 1000 K / W, 1200 K / W, 1500 K / W, 1800 K / W, 2400 K / W, 2800 K / W, 3800 K / W, or indeed, any other desired metric. Note that these metrics / minimums do not need to be the same for each heat flow path; for example, in one embodiment, the non-conductive material of the interposer can be designed to provide the hot region of an ovenized system with a minimum thermal resistance of 2500 K / W, the atmosphere can be designed provide a minimum thermal resistance of 3500 K / W and the conductors can provide a minimum thermal resistance of 15000 K / W, with the dimensions of these various paths being structured so as to obtain an overall thermal resistance to leakage from hot region components.

[0057] The embodiment seen in FIG. 3A also represents a common theme for many of the embodiments discussed herein, namely, where the interposer (and the hot region circuitry) are surrounded by an atmosphere of a nature that reduces thermal leakage and / or renders that thermal leakage negligible. In any given design, this will be a function of at least two parameters, including conductivity of the atmosphere in the cavity / chamber and minimum gaps and distances between hot regions and adjacent walls and structures (such as represented 310a, 310b and 310c in FIG. 3A). For example, in many embodiments (as will be discussed below) a low-conductance, large molecule gas can be used, such that extremely small gaps can be used in combination with this gas and / or near-vacuum pressures; the effective of this design is to reduce thermal leakage through the atmosphere and to channel relatively more thermal leakage from the hot region into the interposer (and associated electrical connections). Depending on embodiment, a Noble gas (e.g., argon, krypton or xenon), a hydrocarbon gas, an inorganic halide or an oxide can be used, where these materials represent at least a target fraction of the molecules in the cavity which is greater than their fraction in ambient air (e.g., outside of the system). In some embodiments, this percentage can be much higher that normal presence of these materials in ambient air, e.g., satisfying 2%, 5%, 10%, 20%, 50%, 80%, 90% or other minimums. As seen in FIG. 8A for example, xenon gas is about five times more thermally-resistive than dry air at normal atmospheric pressures; aided by sufficient minimum gap spacing enforced between structures, atmospheric resistance to heat loss fromSpecification, SA1097-PCT / 2025027the hot region can be raised dramatically. [It is also noted, in this regard, that in practice there is negligible (e.g., no) observed convection in small cavities or chambers on the scale of the integrated circuit scale devices contemplated by this disclosure, e.g., 7.0 millimeters (mm) by 5.0 mm with a height of 2.0 mm, 9.0mm by 7.0mm by 3.6mm, etc.] This is to say, as represented by arrows 308a and 308b in FIG. 3A, the interposer can be suspended in manner of a bridge and / or cantilever, so as to suspend hot circuitry within the (thermally-non-conductive) atmosphere, with the structural coupling of the hot region circuitry only being provided through high-thermal resistance materials of the interposer; the heat of the hot region is surrounded on all sides, and effectively encased, such that a relatively large portion of heat leakage from the hot region passes through the interposer (and, e.g., through the throat region 335 in the case of the embodiment seen in FIG. 3A).

[0058] This design philosophy is conceptually represented in FIG. 3B, which shows a diagram of a heat flow model 341. More particularly, heat flow from structures and / or circuitry in the hot region can be modeled as the sum of (a) heat loss through the atmosphere (gas), i.e., from the hot region to lids, walls and / or base of the package or system, 347, and from there to the ambient environment, 345, and (b) heat loss via the electrical paths and physical supports for the hot structures and / or circuitry, i.e., through interposer 349, and from there, to the ambient environment 345. By restricting atmospheric heat loss and / or reducing that heat flow component, the conductors and / or structure of the interposer can be tailored to specifically shape and / or regulate overall heat leakage from the hot region to a predetermined flow range; in turn, this makes it possible to design power efficient, ovenized systems, e.g., such that maximum temperature change generated by operation of the heat sensitive (ovenized) components is close to maintaining the set point temperature with as little additional heating as possible when the ambient is warmer, while at the same time, efficiently providing for minimal heat loss from hot region components at cooler temperatures.

[0059] It is noted, in passing, that in a typical system, aging and other effects can result in the unwanted release of hydrogen, oxygen, nitrogen and / or other gases following final device assembly (out-gassing); to counteract this, the system can optionally feature a gettering layer 316 to absorb selective small molecule gasses. Note that an advantage of using a low-thermal-conductivity gas in the system is that outgassing is largely irrelevant if the pressure of the atmospheric gas is significantly greater than the partial pressure of the outgassed molecules.

[0060] FIGS. 3C and 3D are used to discuss heat flow and / or conductor path engineering in connection with the user of an interposer in an ovenized system. More particularly, FIG. 3C shows a first design 351 in which a large central island portion 353 of an interposer mounts a hot circuitry die 355 and provides thermal leakage / heat flow to a terminal bridge 357, i.e., via flow paths 363a and 363b. More particularly, the island Specification, SA1097-PCT / 2025027portion 353 is laterally supported by two tethers, 359a / 359b, which connect to lateral arm portions of the interposer 361a / b. In this regard, a distance 365 between the island portion 353 and the terminal bridge 357 is structured so as to observe minimum gap sizes, as just discussed above, such that thermal flow is emphasized through the interposer material (e.g., a glass, polymer or substrate material) and through the substantial length of the flow paths 363a / 363b. In this regard, the depicted gaps in between bends / turns in the serpentine path of the interposer can be formed by milling slots or trenches in the interposer during interposer fabrication. FIG.3D represents a still more intricate path design 371 in which, once again, a central island portion 373 supports a hot region IC 375, and lengthy flow paths channel heat leakage / heat flow to follow paths 383a / 383b to a terminal bridge portion 377. It is at or adjacent this bridge portion that the interposer is structurally mounted or otherwise thermally couples to cold region circuitry. Once again, in this example, slots or trenches can be milled during interposer design to enforce a minimum gap size 385, e.g., in the presence of a controlled atmosphere, as discussed above. However, it is noted that this embodiment also illustrates a case where the interposer is engineered, in terms of path lengths, aspect ratios, materials and widths, so as to implement a flexible suspension and / or to implement a phononic crystal, i.e., to inhibit coupling of specific vibrational frequencies. For example, it is known that in electronic systems, certain electronic components (e.g., some capacitors) can generate unwanted vibration; in some cases, the frequencies of these vibrations can interfere with the proper operation of other system components and / or create electrical noise. To address this, the interposer structure in some embodiments is also designed with flexibility having an associated spring constant (or other design) that effectively rejects coupling at specific frequency ranges. This type of rejection is generally discussed at length in the incorporated by reference document, US Patent Publication No. 20250011162; briefly, the design principles for electrical mounts disclosed by that document can be extended to interposer design (i.e., whether or not including electrical conductors). This objective, and associated design particulars (e.g., spring constant) are conceptually represented by the presence of the letter "k" at the right side of FIG. 3D. The interposer can also be designed, irrespective of flexibility, to have a structure that functions as a phononic crystal, i.e., such that the labyrinthic shape depicted in the FIG., and associated materials, dimensions, aspect ratios, turn radii and so forth, create vibrational reflections that reduce the transmission of specific frequency ranges; designing an interposer path pattern adapted to inhibit transmission a specific shock type or vibrational frequency range is considered within the ordinary level of skill in the art.IV. Packaged Integrated Circuit Implementations Of An Ovenized System.

[0061] FIGS. 4A and 4B are used to discuss specific embodiments of packaged integrated circuit devices which implement ovenized systems.Specification, SA1097-PCT / 2025027

[0062] More particularly, FIG. 4A is a block diagram showing functions and layout in one embodiment 401 of an ovenized system. " Hot circuitry" 431 is depicted at the left-hand side of the FIG., and is seen to include a temperature-sensitive component, a heater / heating element, a temperature sensor of some type, and other hot circuitry (which, by nature will vary depending on application). For example, in an embodiment where the system is a MEMS gyroscope, the system can include electronics which are driven to vibrate small structural bodies with driving and following masses, where the orientation of the following mass, and associated positional sense, is structured so as to sense inertial change in one of six possible degrees of freedom, and also to process an output signal representing sensed motion. In the case of an oscillator (e.g., MEMS-based or otherwise), electronics can include circuitry to generate and maintain a resonator at a resonant frequency, and also to output a frequency reference based on that resonant frequency; associated electronics can include various switching, shielding and / or biasing circuits, as pertinent to the particular design. As is known to those having skill in the art, different types of sensors have structures and electronics that are kept in close proximity to one another and that can be heated to a set-point temperature, to moot temperature dependent variation in the behavior of those structures and / or electronics; in some embodiments, the various structures and circuits represented by function block 403 can be implemented as a monolithic integrated circuit, as a stack of such circuits, or as some other combination of elements (e.g., a circuit and a quartz crystal oscillator).

[0063] As was the case in prior embodiments, an interposer (not seen in this FIG.) is used to regulate thermal leakage and exit. The presence of this interposer is conceptually represented by dashed-line ellipse 407 in the FIG., i.e., with associated regulation of heat from the hot region structures and circuitry to cold region structures and circuitry, the latter being represented by function block 405. As noted earlier, the "cold region" encompasses the ambient atmosphere as well as any components, structures and / or circuitry that are not heated to the set point temperature, e.g., it can include elements at ambient temperature, as well as elements at a temperature in between the set point temperature and ambient (e.g., heated by the operation of various circuits and / or devices including, without limitation, by heat transfer from the hot region). As textually represented in block 405, specific cold region structures and components can include signal conditioning circuitry, heating control circuitry, circuitry to interpret temperatures sensed by the temperature sensor (e.g., to generate feedback), digital circuitry (e.g., memory and gates or circuits which implement digital functions, including without limitation, input / output control, programming and various other logic functions), and many other types of circuitry. As denoted by a communication flow path in the middle of the FIG., electrical signals in this embodiment are routed through conductors that are part of the interposer, and these can also be engineered to provide a selected range of thermal conductance (i.e., heat loss) from the hot region circuitry. The electrical signals passed through this region are seen in the depicted case to include a temperature-sensitiveSpecification, SA1097-PCT / 2025027component output signal (e.g., a resonator signal to be used as a reference frequency), a temperature signal from the temperature sensor (e.g., representing instantaneous, sensed temperature within the hot region), a control signal used to actuate the heater / heating element, and other associated communications (which, once again, can vary according to application). For example, in a system based on an electrostatic MEMS resonator design, some designs can feature a bias control or similar signal, used to adjust resonator performance.

[0064] FIG. 4B is a block diagram showing an embodiment 421 of a packaged integrated circuit device that is an OCXO, specifically, a TCOXCO. One or more hot region dies 421 support one or more heating elements, two MEMS resonators, and sense and sustain circuitry for each of the two resonators. In one design, one or both of the resonators can be electrostatic MEMS resonators, while in other designs, one or both of the resonators can be piezoelectric MEMS resonators. As graphically depicted in the FIG., a first one of the MEMS resonators is designed to have a relative flat temperature response, while a second one of the MEMS resonators is design to have a strongly varying (but ideally, a monotonic and linearly varying) resonant frequency, as a function of current temperature. Reference signals carrying the pertinent resonators' resonant frequency travel from the pertinent sustain circuitry through the interposer 427 to cold region circuitry, where a ratio between the two resonant frequencies is identified and used to exactly identify temperature (i.e., by a temperature derivation block). A high-precision temperature signal is then used to drive heating control, with one or more heating control signals being passed back through the interposer to control the heating element(s) in the hot region. The high-precision temperature signal can also optionally be used (e.g., in a TCOCXO design) to identify frequency correction factors from on-board digital memory, for fine tuning of frequency of an output oscillation signal; this is electronically implemented by a frequency synthesis block (represented in the FIG.). In some designs, the oscillator can have a programmable output frequency, with frequency scaling parameters being received by the oscillator from externally-provided programming, and then used to control by a programmable oscillation block (e.g., frequency can be scaled using a multiplier or divider, such as based on an nPLL, via digital frequency synthesis or interpolation, or in some other manner). In some embodiments, the flat temperature resonator is a 16 megahertz (MHZ) or 32 MHZ resonator, and the OCXO generates an oscillation signal that is some multiple or fraction thereof. In still other embodiments, a multifunction interface permits programming and input / output of signals (including an oscillation signal) using a minimum number of IC pins or output pads (429), for example, for power and ground connections, for one or more separate oscillator signals, and for serial binary communications used for programming and for digital communications. As conceptually represented by a dashed-line path 431, some external control signals can be directly passed between the external IC pins / pads and the hot circuitry (i.e., through the interposer); by way of example, a control signal can be used for thermal characterization at the factory, where the heating element is used to simulate a range of temperatures (e.g.,Specification, SA1097-PCT / 2025027both inside and outside the rated range of an electronic product, and / or 'around' the set point temperature), while resultant oscillation and / or resonator frequency are recorded, where correction factors are then empirically identified (i.e., for each oscillator product on an individualized basis), and where those correction factors are then programmed into memory of the specific TCOCXO IC.V. Cantilevered Suspension (Isolation) Of Hot Region Structures And Circuitry In An Ovenized System.

[0065] With some exemplary applications and / or system designs thus being introduced, this disclosure will now proceed to examine some further options for interposer design, manufacturing and / or installation. It is noted that other options and variations will be apparent based on the discussion that follows, many of which are discussed in the priority documents. Without limitation, this disclosure expressly contemplates each possible combination and / or permutation of these features, i.e., no element of any embodiment is to be considered "essential" for any embodiment.

[0066] FIG. 5A shows a side view of a packaged integrated circuit device 501 having a base 503, a lid 505, and a cavity or chamber defined in between the base and the lid. As with the other embodiments discussed herein, in some cases the cavity or chamber is hermetically sealed (although this is not required for some embodiments). In this particular case, the cavity or chamber can contain a controlled atmosphere 508 with a high-thermal resistivity; this atmosphere can feature a Noble gas at atmospheric or reduced pressure, as previously discussed, or one of the other low-thermal-conductivity gases discussed herein. Also, dependent on the atmosphere used inside an ovenized device, the cavity or chamber can optionally include a getting layer 516 to absorb residual gases that are released into the cavity or chamber following fabrication. FIG. 5A once again shows hot and cold regions 509 and 511 of an ovenized system, where these regions have respective chips or chip stacks. For example, in a MEMS device, the hot region can include a hot circuitry die 515 and a MEMS die 517, and the cold region can include a cold circuits die 521 (e.g., having signal processing circuitry and general system control circuitry, as previously discussed). Optionally, these various dies can be made using respective process technologies (e.g., BiCMOS and CMOS, respectively, with different line sizes, and so forth), although this is not required. The dies 515 and 517 in the hot region are seen to respectively have a heating element and a heat sensor, with one of these being referenced by numeral 518 and other by numeral 520; it is possible to have both of these elements in a common one of the dies (e.g., represented by either numeral 518 or 520); further, in some embodiments, the depicted die position can be flipped (e.g., with a MEMS die on the bottom). In a case where the MEMS die 517 represents a dual-MEMS architecture, typically, two resonators in the MEMS die 517 will operate as the temperature sensor of the ovenized system and the heating element will be in the hot circuitry die 515, near its surface, close to an interface between dies (as referenced by numeral 520). In the Specification, SA1097-PCT / 2025027case of FIG. 5A, the two hot region dies 515 and 517 are seen to be electrically mounted by solder mount connections 523a (e.g., solder balls, although other conductive bonded connections can also be used). This mounting can be supplemented by a non-electrically conductive but thermally-conductive underfill or epoxy 524, which "thermally shorts" the heating element and the MEMS elements (or other temperature-sensitive elements) in the adjacent die. Note that in contemplated embodiments, other types of temperature sensors are used, including without limitation a thermistor (which can be located in either die, depending on implementation). A second set of solder mounts (e.g., solder balls or other conductive and non-conductive bonded connections connections) 523b electrically and physically mount the hot region die stack to interposer 513, optionally also with a conductive underfill (i.e., similar to underfill 524). Note that, while die 521 in the cold region is similarly seen mounted by solder connections or other conductive bonded connections 523c, it is also possible to use wire bonds or other connections or to use diverse combinations of connection types. The interposer 513 also has connection pads 525 on its surface, to receive electrical signals from the hot and cold region circuitry, with electrical paths or conduits 533 connecting these connection pads together within the interposer (and optionally to hot region circuitry directly with one or more external pins; this is denoted by the presence of path 526). Once again, electrical connections and heat flow are channeled by the interposer 513 through high-thermal resistance, which is represented in the FIG. conceptually as throat region 535; the region can optionally represent serpentine or labyrinthic routing, different material layers, and / or provide a flexible suspension, and so forth. In the depicted embodiment, it is assumed that the interposer is either a monolithic or multilayered assembly of high-thermal-resistance materials, for example, made of glass, ceramic or a suitable polymer, with a high-thermal-resistance material forming at least a top layer of the interposer, i.e., in a manner abutting and / or encasing the conductive paths. In the depicted embodiment, a physical offset structure, configured as a pair of shoulders 529, supports the interposer. The interposer can be bonded to these shoulders using a solder mount or other conductive bonded connections mount 528, with vias or other electrical routing within the shoulders being used to convey electrical signals 532 between the various circuitry of the system and external contact pins 531 of the packaged integrated circuit. Note that only one shoulder or offset 529 is seen in the FIG.; in the depicted embodiment, the interposer extends into the drawing page as a cross bar, with the interposer being supported at either end by a shoulder or physical offset (see, e.g., FIG. 5B or 5F, below). Once again, in this design, the interposer 513 acts as a bridge or cantilever which positions the hot region within the cavity or chamber in a manner enclosed by a controlled atmosphere on at least four sides; this presents a high-thermal-resistance path for heat transfer from the hot region. This structure also facilitates engineering of the interposer 513 to provide for an engineered range of thermal resistance from the hot region via structural elements (as contrasted with atmosphere inside the cavity or chamber).Specification, SA1097-PCT / 2025027

[0067] With this embodiment, as well as many of the other embodiments discussed herein, the use of a controlled atmosphere should be considered optional. This is to say, atmospheric thermal resistance can be made large as a function of spatial distances between the hot region and surrounding structures; if large enough spatial distances are used, even ambient air can potentially be employed as the atmosphere within an ovenized system and, indeed, some contemplated embodiments do have such an atmosphere. The use of a controlled atmosphere, however, as defined herein, enables smaller device fabrication and / or higher atmospheric thermal resistance values, which in turn, facilitates interposer design to engineer hot region heat leakage.

[0068] FIG. 5B shows a side view of another embodiment 535 of a packaged integrated circuit device, once again representing an ovenized system. As seen, the system includes a base 537 and a lid 539, which define a cavity or chamber 545 therebetween, and a sealing ring 541 formed at the interface between the lid and the base; this sealing ring, for example, can optionally be a metallic mount that is resistant to small molecule penetration (e.g., hydrogen or helium), or a small molecule barricade or "moat" structure. The cavity or chamber can once again optionally include a gettering layer or material 542 to absorb residual gas released from materials following cavity / chamber enclosure and / or hermetic sealing. As with the other structures disclosed herein, many materials can be used for these various structures and elements, some of which are detailed in the various documents which have been incorporated by reference; without limitation, it is expressly contemplated that the features of this embodiment and the various incorporated-by-reference documents, can be mixed or matched in any desired permutation or combination. In this example, once again, an interposer acts as a bridge or cantilever, suspending hot region circuitry 546 in a manner substantially surrounded by atmosphere, with minimum gap spacings enforced relative to surrounding walls and structures, as is conceptually represented by arrows 545a and 545b. The circuitry of the cold region 547 is illustrated in a dashed-line format, conceptually representing that it is positionally-offset from the hot region circuitry 546 atop the interposer in along the direction that extends into the drawing page. The interposer, in turn, is mechanically mounted within the cavity or chamber on shoulders 542a and 542b; note that the text " CR" appears adjacent the base at either end of the structure, i.e., to indicate that the base (and ambient) are considered part of the "cold region." As denoted by numerals 543a and 543b, in this embodiment, the interposer can optionally feature a layer of glass, ceramic or a suitable polymer as a top material layer 543a, riding atop a supporting layer of other material; as with embodiments discussed previously, the interposer can have buried electrical paths or conduits, or ones that are formed as surface traces.

[0069] FIG. 5C shows another side view of a possible packaged integrated circuit design 551. This embodiment once again includes a base 552 and a lid 553, which define between them an operating cavity or chamber. The base and lid are once again bonded / mounted together using a hermetic bonding process (e.g., Specification, SA1097-PCT / 2025027using materials referenced in the priority documents), with these materials forming a sealing ring 554 to enclose and / or hermetically seal the chamber or cavity. In this particular example, hot region circuitry is mounted directly atop an interposer 555, with the interposer being mounted as a bridge vertically above cold region circuitry, as depicted (e.g., above cold region IC 561). In this particular example, two hot region dies 562 and 563 are seen in a stacked relationship; these dies are wire bonded to each other and die 562 is wirebonded to electrically connect to contact pads and routing 559 on the interposer. Power and communications are routed through vias 555a within each of two vertical columns 555b. In this example, the interposer can be considered to include these columns 555b as well bridge portion 555c, with the bridge portion and the vertical columns being optionally formed using a process referenced with respect to FIG. 15A-15B; in some embodiments, thermal regulation is performed in the bridge portion 555c only, with the columns 555b serving only as vertical standoffs or otherwise forming a part of the base 552. As with prior embodiments, the minimum gap distances between structures can be enforced such that the atmosphere within the chamber provides a high thermal resistance to heat leakage from the hot region circuitry, and such that a desired portion of the thermal leakage from the hot region is channeled through the interposer and its associated conductors. The circuitry and structures within the hot region can be protected from damage during and post-assembly by encapsulation, e.g., as represented in the FIG. by the presence of a glob of plastic encapsulant 564. The routing of power and communications to cold region circuitry can be achieved using base contact pads 557, with conductive layering and / or electrical conductors 568 effective to transfer power, payload and communications through the base to and from external contacts 567. In some embodiments, the atmosphere adjacent to the cold circuitry is exactly the same (and freely corresponds with) the atmosphere adjacent to the hot circuitry, such that the hot region and the cold region once again share the same cavity or chamber; this is not required for all embodiments, however.

[0070] FIG. 5D shows another embodiment 571 of a packaged integrated circuit device. As with the immediately previous example, this embodiment features a bridge 573 and vertical columns 574, with either the bridge 573, the vertical columns 574, or both, providing thermal regulation and serving as a modular Interposer structure. This depicted embodiment differs from prior example in two noticeable respects: First, the hot die circuitry (i.e., the stack of dies 575 / 576) is now seen mounted together using solder mounts (or other conductive bonded connection) 577, in combination with a thermally-conductive adhesive 578; Second, a hot region assembly (575 / 576 / 577 / 578) is now seen as flip-chip mounted relative to the bridge 573. Note that as was the case previously, die 575 can include a heater (heating element) and / or a temperature sensor 578. In one embodiment, the top die 575 in the FIG. can be a hot region circuitry die (e.g., a CMOS die) and the bottom die 576 can be a MEMS die; these stack positions can be inverted, or different structures can be used (e.g., side-Specification, SA1097-PCT / 2025027by-side), dependent on embodiment. Once again, an effect of the depicted structure is that the interposer, especially the bridge 573, mounts the hot region structures and circuitry in a suspended manner within the atmosphere. Here too, the atmosphere can optionally be a controlled atmosphere having a high-thermal resistance to heat leakage, for example, featuring a large-molecule, chemically-stable gas (e.g., a Noble gas, such as argon, xenon or krypton, a hydrocarbon gas, carbon dioxide or another oxide, an inorganic halide, and so forth), in a fraction of the total molecules present greater than naturally present in ambient air. In other embodiments, the controlled atmosphere can instead or in addition be configured as a partial vacuum.

[0071] FIG. 5E shows another embodiment 581 of a packaged integrated circuit device; this time, the cold region circuitry (e.g., IC 585) is shown as mounted vertically above the hot region circuitry in a manner supported by a bridge, e.g., directly over or partially over a hot region die stack 583. In this case, the interposer 586 is typically mounted at a lower level, again, such that it directly mounts or suspends the hot region circuitry (hot region die stack 583) within the atmosphere, once again functioning as a bridge or cantilever within the atmosphere. Shoulders or supports which serve as vertical standoffs 588 for the cold region circuitry are illustrated in dashed-line, so as to visualize the hot region structures 583. In this embodiment, the cold region circuitry 585 also rests on its own support frame or bridge 589. As with other embodiments discussed herein, the interposer functions as an engineered heat flow device, i.e., to regulate thermal leakage from the hot region, with the atmosphere preferably cooperating with this function by providing a high thermal resistance (such that a significant percentage of overall thermal leakage from the hot region, ideally, 30%, 40%, 50%, 60%, or more, is channeled through the interposer, e.g., through bridge 585).

[0072] FIG. 5F shows yet another embodiment 591 of a packaged IC device, this time in perspective view. In this particular case, reference numerals show corresponding elements using arrows, i.e., to distinguish conductive traces and wire bonds from enumerated elements referenced in this paragraph. A MEMS die 592 is once again visible atop a CMOS die 593, which contains in integrated heater. The MEMS die is wire bonded to the CMOS die, which in turn is wire bonded to traces on the hot area of a modular shelf 595. The modular shelf, 595, has surface metal traces which electrically connect the CMOS die to electrical pads on a glass substrate 594. The glass substrate is mounted on a shelf in the ceramic package (597), and wire bonds are made to pads on the package shelf (not shown in the figure) which are routed to the exterior of the package and to the cold die as required. As with some prior embodiments, this permits pre-assembly of the hot region structures and circuits, with ensuing modular addition to system or package during assembly / fabrication. Alternatively, the assembly is performed in-situ in the final package. The package lid is not shown in this FIG. Once again, this design suspends hot region structures and circuitry in a manner surrounded on two sides and above and below by a high-thermal resistance atmosphere within the depicted system or package. In this embodiment, the cold Specification, SA1097-PCT / 2025027circuitry shares the same enclosure and / or atmosphere. Once hot region and the cold region circuitry and / or modules have been added, and any ensuing wire bonding completed (e.g., between vertical levels as indicated), the depicted ceramic package 597 can be closed and / or sealed by installation of a lid (not shown), to complete system and / or integrated circuit package assembly.

[0073] FIGS. 6A and 6B are used to show still further variations.

[0074] In FIG. 6A, an interposer is seen as having two components, including a support block 603 and an electronic connection block 605. As with other designs discussed above, the support block can be prefabricated, optionally having hot region components (e.g., die 607 and die 609) already mounted to the support block (e.g., via an adhesive mount 610); these elements can in this event be installed as a modular unit as part of the assembly process. Note, however, that in this embodiment, electrical connections between hot and cold region circuitry can be completed later. This is to say, the electronic connection block can be mounted as a standalone structure or a structure to the support block, e.g., using an adhesive bond, with the electronic connection block then being wire-bonded 621 / 629 to couple hot and cold region circuitry; electrical paths 623 within the electrical connection block (or, e.g., mounted as surface traces thereon) connect reciprocal pins or pads 625a / 625b, to thereby complete electrical connection between hot and cold circuits. As with prior embodiments, the electronic connection block 605 can optionally also be made of a high-thermal resistance material (e.g., such as a glass, a ceramic or a suitable polymer). In this embodiment, the primary structure-based thermal resistance will be provided by the support block portion 603 (e.g., aided by provision of an atmospheric moat or trench 625 and gap spacing 627), while electronic connection block 605 can be engineered as desired to tailor thermal leakage via electrical connections between hot and cold circuitry (e.g., as a thermal flow path which is distinct from a thermal flow path of the non-conductive support block or via the atmosphere within the cavity or chamber). This is to say, the depicted electrical paths 623 within the electrical connection block 605 can be engineered so as to provide a separate "throat region," enabling independently adjustment of electrical conductor-based thermal resistance between hot and cold regions, i.e., through appropriate engineering of the electronic connection block 605.

[0075] FIG. 6B shows another embodiment 651, in which the interposer takes the form of a middle frame 657, sandwiched between a lid 653 and a base 655. In this regard, enclosure of a cavity or chamber (674 and / or 674') can be performed by sealing the lid 653 to the interposer and base (as represented by the depicted presence of a sealing ring 671 between the interposer and the lid); note that these various roles can be reversed and this ordering this example is arbitrary, e.g., if the FIG. is turned upside down, the lid becomes the base and vice-versa, and the position of depicted vias (661) and surface contacts (673) can also be moved to the base. In Specification, SA1097-PCT / 2025027this embodiment, a first hot IC 665 and a cold IC 666 are mounted on one side of the interposer 657 (e.g., using solder mounts or another conductive bonded connections bonding process), while a second hot IC 667 is seen as suspended below the first hot IC 665. As seen in detail in the FIG., the first and second hot ICs 665 and 666 are mounted on opposite sides of a substrate or circuit board 663, and this circuit board is then mounted to the interposer, e.g., via solder mounts or other conductive bonded connections 669; wire bonding can be used in some embodiments to instead supplement an adhesive, structural mount. The depicted substrate or circuit board can also mount other hot region structures, circuitry or ICs, as referenced by numeral 668. In the embodiment seen in this FIG., minimum spatial gaps in the atmosphere are once again enforced using slots or trench structures in the interposer (e.g., at the area represented by ellipse 659), with serpentine or labyrinthic interposer path configuration also being used (e.g., as illustrated in FIGs. 3C and 3D; gaps or trenches of the type illustrated in these latter plan views are not directly seen in FIG. 6B, as they lie perpendicular to the drawing page). In this example, electrical signals to or from contact pins or pads 673 are communicated through the lid 653 by means of vias 661; note again, that any of these relationships may be inverted, such that the base becomes the lid and vice-versa, or such that vias extend through the base, or such that vias extend through each of the lid and the base, as suitable to the application. Unlike some of the other embodiments discussed herein, the use of a central wall 672 optionally permits there to be two different cavities or chambers 674 and 674', i.e., one each for the hot region and the cold region; as has already been noted in connection with other embodiments, these regions can alternatively share a common atmosphere (and / or common cavity or chamber), e.g., with atmospheric communication between cavities or chambers 674 and 674'.VI. Interposer Design Considerations.

[0076] As noted earlier, many of the embodiments discussed herein use a high-thermal resistance atmosphere to reduce atmospheric heat loss from the hot region of an ovenized system and to increase associated thermal flow through an interposer, with an interposer being deliberately engineered such that overall hot region heat leakage (i.e., through the paths of atmosphere, electrical conductor and interposer bulk) meets specific constraints associated with set point heating. Optionally, as indicated by the various embodiments referenced earlier, the interposer can further be designed so as to be a prefabricated modular assembly structure, so as to function as a cantilever or bridge which isolates hot region components in a manner substantially surrounded by the atmosphere, and / or to provide a flexible suspension and / or phononiccell. FIGS.7A-8C are used to discuss some thermal engineering perspectives associated with these tasks.

[0077] First, FIG. 7A shows a first heat flow model 701 that might be used in assessing performance of an ovenized system. Depicted values refer to injected power (i.e., Ph and Pcrefer to power consumed by hot and Specification, SA1097-PCT / 2025027cold regions), effective thermal resistances (i.e., Rhc, Rhb, Rcband Rbarefer to thermal resistances between hot region, cold region, a base (or lid or wall structure), and / or ambient, as indicated by the pertinent subscript) and temperatures (e.g., Th, Tc, Tb and Tarespectively refer to the temperatures at the hot region, the cold region, the base / support structures, and ambient, respectively).

[0078] As noted earlier, a number of the embodiments herein rely on separately modeling heat loss from the hot section of the system as separate heat leakage paths through an interposer's bulk, an atmosphere, and electrical conductors. FIG. 7B shows the system of FIG. 7A broken down into these components. In this model, thermal resistances from the hot section to the base are modeled as separate paths passing through the atmosphere (atml), the non-electrically-conductive parts (or the "bulk") of the interposer ( / nt) and the electrical conductors (coni). Direct heat transfer between the hot and cold circuits is primarily through the atmosphere (although there is of course an additional heat transfer path via the interposer and the base). The cold die is connected to the base by its electrically and thermally conducting connections - which might be the metal bumps in a gold compression bond, for example (con2). In general, it is advantageous for the cold die to be tightly thermally coupled to the base (for example Rcon<30, 20, 10, 5 K / W) so that the cold die dissipates heat primarily through the package base to the ambient. In some embodiments, therefore, the cold die can be directly mounted to the base, or coupled by some intermediate support (e.g., thermally-conductive support), though this is not required for all embodiments. It is also desirable retain significant thermal resistances between the hot and the cold circuits (Rotmz>1000 K / W) and between the hot circuit and the ambient (Rotmi>1000 K / W, Rcom>1000 K / W, Rmt>1000 K / W). If these design guidelines are followed Tc~Tb and the dominant remaining thermal resistances are Ratmi, Ratm2, Ream and Rmt. Many of the embodiments described herein feature a situation where Ratm[i.e., defined by the parallel combination of Ratml& Ratm2, i.e., such that (1 / Ratm)=(l / Ratmi)+(1 / Ratm2)] is designed to be greater than or equal to 1000 K / W, where Rcom is designed to be greater than or equal to 1000 K / W and where R,ntis designed to be greater 1000 K / W. Advantageously the value of RCom can be made significantly larger than 1000 K / W while keeping a balance between Ratmand Rmt, e.g., in order to minimize package dimensions (that is, in a typical case, making / ?otmlarger results in larger volumes of the atmosphere, while making R,ntlarger typically results in a larger interposer). There is, generally speaking, a practical limit on the maximum value of Ratmand Rintimposed by the self-heating of the device due to the basic (non-heater) related power dissipation of the hot circuitry - which limits the maximum ambient temperature for thermal control of the hot circuit.

[0079] In this regard, providing for thermal isolation typically involves a trade-off between the total power dissipated in the ovenized device and the operating temperature range that can be achieved. The hot region circuitry (e.g., the sustaining circuitry in the case of an OCXO) utilizes some power for operation (Ph, min). By way Specification, SA1097-PCT / 2025027of example, considering the situation in which the system of FIG. 7B is designed such that Rcon2<'<' Ratm2 and Tc~Tb, a designer can focus attention primarily on the hot region circuitry, the base and the ambient (i.e., since the cold circuitry is assumed to at approximately the same temperature as the base). In this case, the design can be approximated with a single resistance Rhb between the hot region and base as the parallel combination of Ratmi, Ratm2, Ream and, Rint[such that (1 / Rhb) ~ (1 / Ratmi)+(1 / Ratm2)+(1 / Rcom)+(1 / Rint)]. For large values of Rhb, a larger temperature difference AT,= Ph,min-Rhb develops between the hot circuits and the base / cold circuits. Furthermore, an additional temperature difference AT2= (Ph,min+Pc)-Rba is developed between the cold regions (e.g., a cold circuits die inside the packaged integrated circuit and the ambient environment outside of the packaged integrated circuit). This temperature difference is determined by the properties of the application environment / package / system in which the ovenized system is mounted (for example, the overall system might be actively cooled by a fan, or passively cooled through convection) - these conditions, along with the thermal conductivity of the PCB, determine Rba- This results in a certain temperature difference between the ambient and the hot region, which drives different thermal flow conditions as a function of the minimum power required for operation of the hot circuitry ATEXit=ATi+AT2. If the temperate of the hot region is maintained at a fixed temperature TSet, then the maximum operating temperature for the hot region (and for the ovenized device) is Tset - ATcxit- FIG. 7F shows how the total system power requirement (including, for the purposes of illustration, 20 mW of cold die power consumption) varies as a function of the thermal resistance Rhb when it is assumed (for the purposes of illustration) that Rba=40 K / W (solid-line curve) and Rba=200 K / W (dashed-line curve). As Rhb is increased, the system uses less power at room temperature, which is desirable. In this case, for the purposes of illustration, a hot region at a set-point temperature of 115°C and an ambient temperature of 20°C are assumed. FIG. 7G shows the value of ATEXit when Rhb is varied (for the same two values of Rba),' ATEXH increases as Rhb is increased, which is undesirable as it reduces the maximum operating temperature of the device. When the ovenized system is operated at the cold end of its operating range, less power is required if the thermal isolation created by the interposer design Rhe is large. However, this also results in a larger value of ATEXit (i.e., which will be a function of thermal conductance properties of various elements in the system and the temperature difference between the hot and cold circuitry); since it is generally desired to efficiently attain and maintain the set point temperature with minimal or optimal overall power consumption, there is therefore a trade space between low power operation and the overall operating temperature range. This trade space is illustrated in FIG. 7H, which shows the same data plotted in FIG. 7G and FIG. 7G but with Rhb eliminated. FIGS.7C-7E show plots for an exemplary ovenized system design (based on the design shown in FIG. 5F), in which an internal atmosphere results in roughly 50% of overall thermal leakage and heat loss from the hot region, and in which an interposer's bulk and electrical conductors account for roughly the other half of thermal leakage. TheseSpecification, SA1097-PCT / 2025027plots emphasize the power loss and thermal resistance from the hot circuit to the ambient through the three different mechanisms of heat loss corresponding to Ratm, RCOni and, Rint.

[0080] As illustrated in FIG. 7C, the power required to maintain a hot die at a specific temperature increases as the ambient temperature is reduced. This FIG. shows data obtained from simulations of the example design depicted in FIG. 5F. In such a device, cold region circuitry die is assumed to dissipate 20 milliwatts (mW) of power. FIG. 7D shows how the thermal resistance between hot and cold region circuitry (e.g., hot and cold dies) can be broken into individual components corresponding to heat flow through three hot region heat flow components of the system, i.e., gas (atmosphere) and interposer's bulk (e.g., a glass) and electrical conductors (e.g., wire bonds). The power is computed by summing the heat flux over the interposer and hot region interfaces to the atmosphere, the connections from the conductors to the rest of the circuit and the connection(s) between the interposer and the base / package. Once the power is computed, the resistances can be calculated from the hot stage temperature difference. These resistances are achieved by designing the interposer, cavity gas and interconnects to have thermal resistances over 1000 K / W. In this instance the metal traces are assumed to be 1 micron thick Aluminum with a trace width of 10 microns and a trace length of 630 microns. The glass interposer is 300 microns thick, 800 microns wide and 3.5 mm long from end to end. The glass is assumed to have a thermal conductivity of approximately 1.2 W / m / K. The package is sealed in a Krypton atmosphere (i.e., one atmosphere of pressure with approximately 100% Krypton) and the minimum gap between the interposer and the cold die is 0.26 mm, while the minimum gap distance between the MEMS die and the lid (not shown in FIG. 5F) is 0.37 mm. These dimensions were obtained by iterating on finite element solutions of the package. FIG. 7E shows the thermal conductance for these same three component flows. From these various FIGS., each of the three component flow paths is seen to provide significant thermal resistance, i.e., as an engineered objective; as seen in FIG. 7D, for example, the atmosphere, using the principles introduced above, was engineered to provide a thermal resistance of about 2800 K / W, the interposer's insulative materials were engineered to provide a thermal resistance of about 3900 K / W, and the electrical conductors where engineered, in terms of path length, diameter and other parameters, to provide a thermal resistance of about 19500 K / W. These various parameters, and similar design models, facilitate design of an ultra-low power ovenized system. Note that the material properties in the model are temperature dependent- which can cause the variation in thermal resistance observed.

[0081] As noted, implementations can be designed using this tripartite heat flow model, i.e., by regulating atmospheric loss to a set value (and optionally, a suitable maximum), and then modeling remaining hot region thermal loss through an interposer's bulk and through electrical conductors. In one embodiment, one or more of these heat flow component paths (i.e., atmosphere, interposer (insulator) and conductors) are engineered to Specification, SA1097-PCT / 2025027provide a thermal resistance of no less than 1000 K / W to produce a low power ovenized device; in some cases, all three component flow paths can be engineered to meet this same minimum. In alternative implementations, much higher thermal resistances can be implemented, i.e., no less than 1000 K / W for one or more of the illustrated component heat flow paths; no less than 1200 K / W for one or more of the component heat flow paths; and similarly, no less 2000, 2400, 2800, 3900, etc., as baseline metrics for thermal engineering. These numbers / metrics can be the same for each heat flow component path, or different metrics can be used for different paths. However, as also noted above, these heat flow component paths (and the interposer bulk) are also advantageously engineered so as to also provide the hot region thermal flow meeting the criteria set forth above, e.g., so as not overshoot set point temperature while minimizing power consumption. A skilled designer can, depending on the specific type of ovenized system at issue (e.g., oscillator, gyroscope, sensor, etc.), and depending on the power requirements / constraints needed for the system of interest, utilize these teachings and general skill to arrive at an appropriate atmosphere, minimum gap spacing, interposer design and conductor routing design for a given implementation, i.e., one that produces a high-thermal resistance, low power design.

[0082] FIGS. 8A-8C provide further information that can be utilized as part of this analysis and / or design optimization. More specifically, FIG. 8A shows thermal conductance values (i.e., in Watts-per-meter-per-degree-Kelvin, also referenced as " W / m / K") for various gases (atmosphere types) assuming a normal atmospheric pressure (i.e., 1.0 atmospheres). As observed from this FIG., certain gases provide higher thermal resistance than others - for example, assuming clean dry air (CDA) as a baseline, it is seen that large molecule Noble gases provide significantly greater atmospheric resistance to heat loss, e.g., with Xenon providing the best results and with Krypton also providing good results (e.g., each of these Noble gases exhibits conductivity less than 0.01 W / m / K, while CDA has about three time the thermal conductivity of Krypton). Stepping outside of Noble gases, oxides (carbon dioxide) are also seen to provide reasonably good results large molecule hydrocarbon gases and inorganic halides will also produce similar results due to their low thermal conductivity. FIGS. 8B and 8C provide an example of a single design analyzed with different atmospheres (for the purposes of demonstrating atmospheric thermal loss examples). These FIGS, also show relative contributions to hot region heat loss for a system implementation at different temperatures, with a set point of approximately 115°C; as seen in FIG. 8B, thermal losses at +20°C for a design with 1.0 atmospheres of Krypton were 46.9 milliwatts through the atmosphere, 0.4 milliwatts through electrical conductors and 1.5 milliwatts through the high-thermal-resistance bulk of the interposer. As seen in FIG. 8C, at -40°C, these numbers increased to 72.0 milliwatts through the Krypton atmosphere, 0.7 milliwatts through electrical conductors and 2.6 milliwatts through the insulative materials of the interposer. Each of these numbers and metrics corresponds to low hot region power loss, i.e., potentially enabling an ovenized system design (e.g., OCXO or TCOCXO) having powerSpecification, SA1097-PCT / 2025027consumption of less than 200 milliwatts, less than 100 milliwatts or, in some cases, less than 50 milliwatts. However, for some of power values, the gas might be too thermally isolating; for example, in the case of a high vacuum, the thermal resistance for a 115°C set point temperature might be over 10,000 K / W ( (115C-20CJ / 0.0089W = 10674 K / W ). This means that if the OCXO sustaining circuits require 10 mW to operate, then operation of circuit operation would generate 107°C of self-heating and, consequently, such a system would not operate above an 8°C ambient. Both the dimensions of the gas, and the atmospheric contribution are therefore advantageously balanced so as to regulate the thermal resistance of the system. In this particular geometry, the use of Krypton at 1.0 atmosphere provides a thermal resistance of (115°C-20°C) / 0.0487 W = 1950 K / W. For a circuit consuming power at 10 mW, this corresponds to 19.5°C self-heating and, consequently, allows operation up to an ambient of approximately 95°C. In this regard, one of ordinary skill in the art, in the process of designing an ovenized system fora particular application, advantageously models a given design by simulating power lost through each of the three referenced component paths, as just discussed, and then adjusts atmospheric makeup, interposer materials (and their thicknesses), minimum gap spacings that are to be observed, electrical conductor diameter and path length, power needed for unheated operation of hot region circuitry, and the desired operating temperature range, all in order to arrive at a power-efficient design suited to the particular project requirements at-issue.VII. Vibrational Dampening By The Interposer.

[0083] It was noted earlier that some embodiments leverage the general design of the interposer to also inhibit vibrational coupling at specific frequencies of frequency ranges. FIGS. 9-11 are used to additionally discuss these embodiments. As noted earlier, US Patent Publication No. 20250011162 (USSN 18712420, filed under 35 USC §371 on 22 May 2024 by first-inventor Nicholas MILLER) is incorporated by reference; this document provides additional information relating to mechanical dampening and associated structure design.

[0084] FIG. 9 is an illustrative diagram which shows a basic embodiment 901 of another packaged, integrated circuit device. This device is assumed to have a component 903 with an internal structure 904 which is sensitive to mechanical stress and / or vibration, such as for example, a resonator or a MEMS sensor of some type (inertial, pressure, temperature, etc.). The component is structurally mounted relative to some type of printed circuit board or other substrate 905 used in an electrical system, e.g., solder mounts or other conductive or non-conductive bonded connections. Consistent with some of the embodiments described above, component 903 is also seen to be optionally sealed or encapsulated, e.g., by side walls 909 and a lid 910, though this is also not required for all embodiments.Specification, SA1097-PCT / 2025027

[0085] Mechanical disturbances which might affect or shift the operation of the component can be caused by manufacturing stresses, overall system operation, or from other sources. For example, numeral 906 designates mechanical stress that arises from another part of an overall system, for example but not limited to, the depicted ceramic capacitor 911. This mechanical stress is modeled here as a vibrational frequency fv, however, it should be observed that the techniques disclosed herein are not limited to situations where stress manifests itself a specific harmonic or set of harmonics (indeed, as is known to those familiar with mathematics or physics, even a square wave pulse can be modeled as a superposition of respective harmonics). FIG. 9 also shows a second form of mechanical stress 908, e.g., manufacturing-induced stress, also modeled as a vibrational frequency (fv); the represented vibrations may be the same or different than stress 905 in terms of harmonics, frequencies, durations and / or amplitudes. This second form of mechanical stress 908 is presumed to originate somewhere else than another electronic circuit of the overall system or package. Note that steady-state or quasi-static stresses are included in the discussion, e.g., as vibrations at zero frequency (fv=0). For example, static bending of the substrate 905 is analogous to dynamic bending and identical in the limit that the vibration frequency tends to zero.

[0086] In the depicted embodiment, the component 903 is seen to be operatively mounted by one or more flexible suspension mounts 913 which operatively couple the component to substrate 905; these mounts are graphically depicted as springs or absorbers in the FIG. and, while four such mounts are depicted, it is noted that only one of these is numbered with a reference numeral (913). In the context of this disclosure, the flexible suspension mount is designed into the structure of an interposer installed in the overall system 901, or as some type of coupling therefore, such that at least part of structural path between hot and cold regions is engineered to provide mechanical dampening through manipulation, in terms of interposer materials and dimensions of interposer heat flow paths and / or couplings. Since there may be more than one interposer or interposer component parts depending on design, vibrational dampening can be implemented by appropriate design of any of these parts, or a portion thereof or a coupling therebetween. As observed, in this embodiment, one or more of the flexible suspension mounts can serve double-duty in providing a mechanical coupling operatively between the component 103 and the substrate 105 as well as providing for electrical interconnection between the two. However, this is not required for all embodiments, and it is possible to have separate electrical connections, as symbolically represented by dashed line connection 915. It should also be noted that FIG. 9 shows four springs that represent alternative and / or redundant connections, i.e., denoting that the component may be mounted above or below the substrate or another intermediate structure (e.g., with respect to a lid 910, laterally from one or more side walls 909, relative to a base, or in some other manner).Specification, SA1097-PCT / 2025027

[0087] In one embodiment, the component 903 comprises a quartz crystal resonator and provides an electrical output, generated as a function of sensed resonance frequency of a quartz crystal; this output is represented by numeral 915 in the FIG. In other embodiments, however, component 903 includes one or more MEMS resonators, for example, electrostatic and / or piezoelectric resonators. In other embodiments, there can be two or more resonators and more than two signals; for example, as discussed earlier, it is known to use two MEMS resonators with different temperature coefficients of frequency (" TCF") such that one of the two resonators produces a resonant frequency that varies (preferably linearly) with temperature, while the other provides a primary oscillation signal that is corrected to produce a temperature-invariant timing signal; in such a system, two electrical output signals can be produced, with frequency differences and / or ratios used as an accurate indicator of temperature. It is also possible to use MEMS resonators as pressure, inertial and / or other types of sensors, or for other types of devices. In one embodiment, signal 915 actually denotes two or more signals (e.g., a drive signal and / or a sense signal), which can be interconnected between the component and substrate, PCB or other circuitry using one or more of the depicted flexible suspension mounts 913; one of these signals can also be a temperature signal. As alluded to, component 903 can more generally include all hot region structures in an ovenized system, i.e., it can also represent a built-in heating element, sustaining circuitry and / or other circuitry.

[0088] An interposer which thermally couples an ovenized component and also acts as a cantilever / bridge to support hot region elements can designed to provide some stiffness but also to have vibrational characteristics that will dampen external mechanical disturbances. In some embodiments, these vibrational characteristics are designed so as to have a predetermined relationship to one or more specific vibrational frequencies that are expected mechanical disturbances; for example, some manufacturing standards provide that integrated circuits should be tested against specific perturbations (e.g., a half-sine wave perturbation as in MIL-STD-883 Method 2002.4). In other embodiments, these vibrational characteristics are designed so as to have a predetermined relationship to expected deflection or vibration of a structure in an overall electronic system, e.g., vibrational frequency of another component. The result, as represented by text legends represented in the FIG., is that although mechanical disturbances can occur, the flexible suspension mounts result in dampened and / or reduced mechanical stress on component 903; at the same time, the connections between the component and base and / or lid of the integrated circuit package are such that an unperturbed electrical output of the component 903 is still provided by the packaged integrated circuit device 901 to the external electronics, that is, through and / or notwithstanding the presence of the flexible connection mounts.

[0089] It was earlier noted that an interposer, including any portion and / or coupling which provides spring force dampening or which serves as a phononic crystal, can form a modular system that is differently positioned Specification, SA1097-PCT / 2025027and / or mounted, depending on embodiment. FIGS. 10A-10C show some specific implementations; the structures depicted in these FIGS, are intended to be nonlimiting.

[0090] FIG. 10A shows a first embodiment 1001, in which an interposer and / or associated couplings 1009 are positioned in between hot circuitry (e.g., resonator IC 1003) and a base or other support structure; cold region circuitry, represented by numeral 1005, is seen to be independently mounted, such that the interposer and / or its couplings dampen / inhibit mechanical coupling to the hot region structures and circuitry (i.e., according to spring constants associated with interposer path length design, or phononic cell characteristics, as reference by spring graphics 1011), but not the cold region structures or circuitry. As alluded to by numeral 1013, electrical connection(s) can optionally be provided for separate from any structural support provided by the interposer, e.g., by independent wire bonds.

[0091] FIG. 10B shows a second embodiment 1021, in which an interposer and / or its couplings 1029 are positioned in between both hot and cold circuitry (e.g., resonator IC 1003 and IC 1005) and a base or other support structure 1007; the interposer in this embodiment is designed such that cold region circuitry, represented by numeral 1005, is also directly mounted by the interposer (e.g., as part of a modular assembly), such that the coupling of vibrational disturbances is dampened or inhibited for both sets of electronics. Once again, as alluded to by numeral 1013, electrical connection(s) can optionally be provided for separate from any structural support provided by the interposer or its couplings, e.g., by independent wire bonds.

[0092] FIG. 10C shows yet a third embodiment 3021, in which an interposer and / or its couplings 1033 are positioned directly in between cold region circuitry and hot region circuitry (e.g., in between resonator IC 1003 and cold region IC 1005); the cold circuitry IC 1005, is not independently mounted, and is potentially subjected to unwanted mechanical vibrations that will be filtered out by the interposer and / or its couplings. Again, per numeral 1013, electrical connection(s) can optionally be provided for separate from any structural support provided by the interposer or its couplings, e.g., by independent wire bonds.

[0093] FIG. 11 shows a graph 1101 that illustrates some of the tradeoffs associated with dampening / rejection of unwanted mechanical vibrations, assuming a hypothetical example of a 500kHz disturbance. More particularly, a first data plot 1105 represents admittance, or transmission, of a 500 kHz disturbance as a function of suspension frequency and / or phononic cell properties, and a second data plot 1103 represents peak shock response as a function of these same properties; each axis corresponds to a logarithmic scale. Data plot 1103 corresponds with the right y-axis while plot 1105 corresponds to the left y-axis. The shock response function assumes a half-sine acceleration profile with 0.12ms duration and 30,000g peak value. The dampening / rejection properties of an interposer or its couplings are advantageously designed to minimize Specification, SA1097-PCT / 2025027values of both data plots, e.g., to provide at least a 50% reduction in vibration amplitude and a maximum deflection under shock that is less than about 50 microns; these values correspond to a range 1107, that is, extending between data points corresponding to these two values. In terms of specific dampening, the range 1107 corresponds to a suspension frequency or phononic cell frequency rejection of about 14 kHz through about 290 kHz, once again assuming a 500 kHz mechanical disturbance; these values also equate to roughly between 2.8% and 58% of the modeled disturbance frequency. If it is desired to obtain even greater suppression, e.g., with at attenuation of a least about 90% and a peak motion response of less than about ten microns (assuming the test condition specified), then the properties of the interposer and / or its couplings are designed to provide dampening / suppression in the range of 50 kHz to 150 kHz; this corresponds to a range of about 10%-30% of modeled disturbance frequency. This is illustrated by range 1109 in FIG. 11B. It is generally anticipated that most integrated circuit coupling implementations which make use of a dampening / suppression of the type referenced in this example will conform to one or both of these ranges, although there may be some implementations which do not.

[0094] As noted earlier, the interposer and / or its serpentine and / or labyrinthic routing can be structured so as to act as a phononic cell, i.e., to dampen and / or filter out specific vibrational frequencies or ranges of vibrational frequencies (see, e.g., FIG. 3D). A phononic crystal design, represented abstractly by a complex interposer pattern such as seen in FIG. 3D, can be adjusted in terms of masses, path widths, bends turns, and so forth, to build constructive and destructive vibrational patterns that have a specific, customizable impact on how vibrations (e.g., affecting the cold side of the interposer, adjacent numeral 377 in FIG. 3D) are passed or rejected by the interposer in route to the hot die (numeral 375). In one contemplated embodiment, this concept can be used specifically to design interposer path patterns so as to produce a phononic crystal unit cell which blocks transmission of vibrational frequencies in the 14-20 MHz and 28-37 MHz ranges. Note that other patterns may be used (than depicted or represented by FIG. 3B), and that it is within the ordinary level of skill of a designer familiar with phononic crystals, to design a phononic unit cell and / or flexible suspension that reduces the transmission of specific mechanical frequencies - either to the hot region structures or electronics - or indeed, any other component of an ovenized system.VIII. Manufacturing Considerations.

[0095] FIGS. 12A-16 illustrate manufacturing processes that can be used to fabricate some of the parts and / or systems described in this disclosure. More specifically: FIGS. 12A-12D relate to one possible manufacturing process for an interposer; FIGS. 13A-13E relate to another possible manufacturing process for an interposer, namely, one having slots, trenches, or complex shapes (e.g., such as might be used to provide Specification, SA1097-PCT / 2025027specific heat path routing, dimensions or aspect ratio, or a flexible suspension mount or a phononic cell); FIGS.14A-C relate to another possible manufacturing process for an interposer, namely, one having through-interposer vias or electrical connections (e.g., which can be used in a embodiments such as seen in FIGS. 5A-5F); FIGS. 15A-15G relate to another possible manufacturing process for devices and / or systems, e.g., to assemble the packaged integrated circuit devices of FIGS. 5C-5D; and FIG. 16 is a flow chart showing one assembly method featuring a prefabricated interposer module.

[0096] As noted, FIGS. 12A-12D illustrate steps associated with one method for the bulk formation of interposers usable in some of the embodiments presented herein. More particularly, these steps are associated with an example manufacturing process for a glass, ceramic or polymer interposer. As illustrated in FIG. 12A, the process begins with a flat panel 1201 of the pertinent material, which is bonded (e.g., via a layer of adhesive 1203) to a support carrier or substrate 1205. As seen in FIG. 12B, a patterned metallization layer 1207 is then added, for example, using a masked sputtering process, to form electrically conductive surface traces and bond pads that will provide electrical connections and / or mount circuits and other structures. In FIG. 12C, individual interposer products 1209a, 1209b and 1209c are singulated, optionally with integrated circuits 1211 (e.g., hot or cold region ICs) mounted thereon (e.g., before or after singulation). Note that in some contemplated package / system assembly methods, any supported ICs can optionally be added prior to the mounting of an interposer in a package or system; in other contemplated package / system assembly methods, an interposer can mounted in the package or system first, followed by ensuing circuit installation and / or electrical interconnection. Finally, as seen in 12D, the support carrier or substrate from FIG. 12A and associated adhesive are seen as removed, leaving finished interposer modules 1213a, 1213b and 1213c that are ready for package / system assembly.

[0097] FIGS. 13A-13E illustrate steps associated with another manufacturing method. Here also, one begins with a flat panel bonded to a support carrier, as was discussed in connection with FIG. 12A. In this embodiment also, a glass, a ceramic or a suitable polymer can be used, although, as the interposer under manufacture is to be patterned, an etchable or otherwise easily-patterned, high-thermal-resistance material can also advantageously be chosen. A patterned mask layer 1301 is deposited or laid atop this assembly, as indicated in FIG. 13A. Then, as observed in FIG. 13B, the high-thermal-resistance material is etched, cut or otherwise milled, for example, to form slots and trenches 1303 / 1305; this process can, once again, be used to define an interposer having a complex shape (e.g., as was seen in FIGS. 3C and 3D), e.g., define a phononic crystal unit cell, a suspension mount or another heat-routing pattern or shape, as was described above. In these FIGS., numeral 1303 represents cuts and / or patterns that will result in respective interposer products, whereas numeral 1305 references slots or cuts within a single interposer product, i.e., at locations where the high-Specification, SA1097-PCT / 2025027thermal-resistance material experiences a bend, turn, or crossmember structure out of the plane of the drawing page. Note that, as an alternative to the steps represented by FIGS. 13A and 13B, it is expected that some high-thermal resistance materials can simply be molded to have a suitable shape. Whichever process is used, and with any masking removed, per FIG. 13C, metal patterning 1307 can then be added atop the high-thermal-resistance material, as per numeral 1307. In FIG. 13D, individual ICs 1309 are optionally mounted atop the metal patterns / bond pads, for example, using a solder or other conductive bonded connection, resulting in distinct interposer assemblies 1311a, 1311b and 1311c. Finally, as seen in FIG. 13E, the support carrier or substrate and adhesive layer from FIG. 13A are then removed, leaving finished interposer modules 1313a, 1313b and 1313c that are ready for package / system assembly.

[0098] FIGS. 14A-14C are used to illustrate process steps where an interposer is built to have through-vias, or electrical connections that traverse through the plane of the interposer, enabling the interposer to mount a die or circuitry on one side and to be bonded to a support structure on the other side. Specifically, FIG. 14A shows an assembly where a high-thermal resistance material 1401 is manufactured or processed to have through-layer vias 1403; also, during or following this manufacturing or processing step, metalized pads or mounts 1405 are deposited on a bottom side of the interposer bulk 1401, and a smoothing or filler material layer 1407 is then added to this surface. Finally, this surface is then adhered to a support substrate or carrier 1409 as has previously been described in connection with FIG. 12A. As noted earlier, this can result in the presence of an observable interconnection or adhesive layer 1411, which will be removed later in the manufacturing process. As best seen in FIG. 14B, a patterned metallization layer 1413 is then formed or deposited, i.e., to define top surface conductive traces and bond pads; milling, etching or pattern definition is also performed, to define individual interposer product shapes and associated slots, trenches, or heat flow structures, each as was described above in connection with FIGS. 13B and 13C. Note that this also results in preliminary definition of individual interposer products 1415a, 1415b and 1415c, to which integrated circuits and / or structures 1416 can be bonded / attached, as was previously described. Notably also, in this step, the bond pads are preferably deposited so as to establish electrical communication with the through-interposer vias 1403 (see FIG. 14A). Finally, as seen in FIG. 14C, the support carrier or substrate, the adhesive layer and any smoothing layer (from FIG. 14A) are then removed, leaving finished interposer modules 1417a, 1417b and 1417c that are ready for package / system assembly.

[0099] FIGS. 15A-15H are used to illustrate assembly of a complete ovenized system, e.g., of a packaged integrated circuit device. The process beings with formation of a rigid-flex interposer or a glass interposer 1501, which will serve as the primary high-thermal-resistance material of the interposer. As seen in FIG. 15A, this interposer material 1501 is mounted to a rigid substrate or printed circuit board 1503, which has walls 1504, Specification, SA1097-PCT / 2025027cavities 1505 and vias defined therein; the vias are not illustrated in these FIGS, to simplify description (but see FIGS. 5C-5D). Although this description and accompanying figure illustrate a specific rigid-flex assembly, the same process may be applied to a support glass interposer with or without vias in the rigid support PCB. In some embodiments, the vias are coupled to interconnects located on an exposed underside of the interposer structure, thereby enabling electrical communication. The rigid portion of the PCB can have a desired thickness to facilitate later manufacturing / assembly operations. Then, as seen in FIG. 15B a hot region die stack 1508 is attached and electrically connected to surface pads and routing. This die stack can feature multiple dies already mounted together, with electrical interconnection between these dies already established, or a latent connection process can then be performed, for example, by adding wire bonding 1509; finally, as referenced by numeral 1511, a glob of plastic or other encapsulant can be added, to protect the hot IC circuitry (note that atmospheric leakage will still be regulated by an atmosphere, e.g., a controlled atmosphere, outside of this assembly, and added during the lid bonding step). As seen in FIG. 15C, individual products 1513a and 1513b are then defined by a milling or cutting process; these singulated products can then be placed on a carrier 1515. The result is a set of first modules 1517a and 1517b, each including hot region components, an interposer and associated electrical routing, that will then be utilized assembly of packaged, integrated circuit devices. Next, as seen in FIG. 15E, individual "cold ICs" 1519 are mounted onto another printed circuit board 1521; as seen in the FIG., this printed circuit board (which will serve as a package base) already has external electrical contacts 1523, contacts for solder or other conductive bonded connections 1525 to interface with the cold ICs 1519, contacts 1527 for compression / thermosonically bonded interconnects (or other applicable conductive bonded connections) that will interact with the vias in the rigid printed circuit boards present in the first modules from FIG. 15C, and contacts 1529 that will be used for lid bonding and final package sealing (appropriate hermetic processes for lid bonding include welding (e.g., resistance, laser, seam), eutectic bonding, soldering, TLP bonding, glass-to-metal sealing, glass frit sealing, or brazing). Note that electrical routing within the printed circuit board 1521 (e.g., through-package routing, or a lead frame which connects mounts 1525 with external electrical contacts 1523) are not seen in this FIG., to simplify discussion (but, e.g., see the discussion of FIGS. 5C-5E, above). Per FIG. 15F, the lid modules 1517a and 1517b, minus their associated carriers from FIG. 15D, are then added to this assembly; note that these lid modules each form a modular interposer assembly with hot region structures and circuitry already installed. The conductive bonded connections 1531 result in electrical connections between the hot region components and cold region components. Finally, lids 1533a and 1533b are sealed in the presence of a vacuum or other controlled atmospheric conditions, resulting in a controlled atmosphere 1535a and 1535b in each of respective finished products 1537a and 1537b. These products have all electrical connections installed, with desired atmospheric makeup, and are ready for thermal characterization, testing and other qualification, prior to final distribution.Specification, SA1097-PCT / 2025027

[0100] FIG. 16 shows a block diagram 1601 showing steps in one method of assembling a packaged integrated circuit device or other ovenized system. As indicated by numeral 1603, an interposer is fabricated and / or cut from desired materials (e.g., a high-thermal resistance material, such as a glass, a suitable polymer or a ceramic material). As noted by a dashed-line (optional) process block 1605, in one embodiment, this material can be created from a processing step, for example, to modify the material's thermal conductance properties. Per block 1607, if relevant to the pertinent interposer design, conductive traces and / or electrical conduits can also be deposited and / or fabricated as part of this step or prior to 1603. FIG. 16 also indicates an optional step 1609 of structurally and / or electrically mounting hot and / or cold region circuitry to the interposer, prior to package assembly; in this regard, it will be recalled that some assembly methods utilize modular integration of an interposer assembly into a packaged integrated circuit (i.e., where the interposer assembly already has mounted circuitry), while in other methods, and interposer is integrated first, with standalone or interposer-mounted circuitry or electrical connections being added later. If an interposer module having premounted ICs is to be used in the assembly process, step 1609 is where this pre-mounting occurs in this embodiment. As referenced by numeral 1611, wire bonding, solder mounts and / or other conductive bonded connections can be used to complete each electrical connection. An interposer assembly (with or without mounted ICs, depending on embodiment) is then mounted to a base, per numeral 1613. As referenced by numeral 1615, any standalone components (for example, cold circuitry ICs not mounted by the interposer, or mounted by an independent bridge) can also be mounted to the base or the interposer at this time, i.e., before, during or after interposer integration with the base (1617). Then, as indicated by numerals 1619 and 1621, any remaining standalone components or other assemblies are also mounted, and any remaining electrical connects are completed. In this regard, as was discussed earlier, in some embodiments, the interposer assembly will have underlying bond pads to receive solder or other conductive bonded connections which will electrically link the interposer assembly to the base; such bonding, if appropriate, now occurs as part of this mounting step. In other embodiments, interposer electrical connection can be provided by wire bonds added after mechanical mounting, e.g., to physical offset structures within the base, as has previously been described. For structurally mounting the interposer assembly to a frame or nonreactive material of the base (e.g., an insulator, plastic, or other material), an adhesive may be used to secure the interposer assembly in place. Finally, the packaged integrated circuit device or system is ready for enclosure, sealing and / or lid bonding, as indicated by numeral 1621; as indicated by numerals 1623 and 1625, this process can optionally feature a hermetic-sealing process, e.g., in which sealing or bonding occurs within a controlled atmosphere, which is thereby sealed inside a cavity or chamber, as has previously been described. Once again, the result is a finished ovenized system (e.g., a packaged integrated circuit device) that is ready for thermal characterization, testing and qualification, prior to final distribution.Specification, SA1097-PCT / 2025027IX. Closing Thoughts.

[0101] The circuits and techniques described above may be further constructed using automated systems that fabricate dies and / or integrated circuits, and may be described as instructions on non-transitory media that are adapted to control the fabrication of such integrated circuits. For example, the components and systems described may be designed as one or more integrated circuits, or a portion(s) of an integrated circuit, based on design control instructions for doing so with circuit-forming apparatus that controls the fabrication of the blocks of the integrated circuits. The instructions may be in the form of data stored in, for example, a computer-readable medium such as a magnetic tape or an optical or magnetic disk or other non-transitory media as described earlier. Such design control instructions typically encode data structures or other information or methods describing the circuitry that can be physically created as the blocks of the integrated circuits. Although any appropriate format may be used for such encoding, such data structures are commonly written in Caltech Intermediate Format (" CIF"), Calma GDS II Stream Format (" GDSII"), or Electronic Design Interchange Format (" EDIF"), as well as high level description languages such as VHDL or Verilog, or another form of register transfer language (" RTL") description. Those of skill in the art of integrated circuit design can develop such data structures from schematic diagrams of the type detailed above and the corresponding descriptions and encode the data structures on computer readable medium. Those of skill in the art of integrated circuit fabrication can then use such encoded data to fabricate integrated circuits comprising one or more of the circuits described herein.

[0102] In the foregoing description and in the accompanying drawings, specific terminology and drawing symbols are set forth to provide a thorough understanding of the present technology. In some instances, the terminology and symbols may imply specific details that are not required to practice the technology. For example, although the terms "first" and "second" have been used herein, unless otherwise specified, the language is not intended to provide any specified order but merely to assist in explaining elements of the technology. In some instances, the terminology and symbols may imply specific details that are not required to practice those embodiments. The terms "exemplary" and "embodiment" are used to express an example, not a preference or requirement. Moreover, although the technology herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the technology. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the technology.Specification, SA1097-PCT / 2025027

[0103] As noted earlier, various documents have been incorporated into this disclosure by reference. The definitions provided by this disclosure are to control (i.e., predominate over any definitions in the incorporated by reference documents) in the event of any inconsistency or conflict, implicit or otherwise, with the meaning of terms as used in this document.

[0104] Various modifications and changes may be made to the embodiments presented herein without departing from the broader spirit and scope of the disclosure. Features or aspects of any of the embodiments may be applied, at least where practicable, in combination and / or permutation with any other of the embodiments or in place of counterpart features or aspects thereof, and each is to similarly be considered "optional" as to any embodiment and / or combination / permutation. Accordingly, the features of the various embodiments are not intended to be exclusive relative to one another, and the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.Specification, SA1097-PCT / 2025027

Claims

CLAIMSWe claim:

1. (Original) An oven-controlled oscillator (OCXO) integrated circuit device comprising:a cavity;a base and a lid substantially enclosing the cavity;an interposer device and a controlled atmosphere in the cavity;a resonator in the cavity and circuitry operable to drive motion of the resonator and to output a resonator signal representing a resonant frequency of the resonator during operation of the OCXO integrated circuit device, the resonator and the circuitry positioned in a hot region within the cavity, the hot region to be heated, during operation of the OCXO integrated circuit device, to a set point temperature;a processing circuit operable to receive the resonator signal, and to generate an oscillation signal, dependent on the resonant frequency, for output by the OCXO integrated circuit device via an external electrical contact of the OCXO integrated circuit device, the processing circuit positioned in a cold region of the OCXO device; andthe interposer device having two or more electrical paths which thermally-couple the hot region with the cold region and, for each respective one of the electrical paths, a respective first contact electrically-coupled with the hot region, using one of a solder mount, a bonded conductive connection, or a wire bond, and a respective second contact electrically-coupled with the processing circuit, using one of a solder mount, a bonded conductive connection, or a wire bond, each respective one of the electrical paths electrically-coupling its respective first contact and with its respective second contact;wherein the hot region is thermally isolated from the cold region by a combination of the interposer device, the controlled atmosphere and the electrical paths, and wherein the combination is structured such that a thermal resistance from the hot region to the cold region is no less than 1000 Kelvins-per-meter (K / W) via the interposer device, no less than 1000 K / W via the controlled atmosphere, and no less than 1000 K / W via the electrical paths.

2. (Original) The OCXO integrated circuit device of claim 1 wherein:at least one of the electrical paths comprises a conductive surface trace; andthe controlled atmosphere comprises a Noble gas which makes up at least two percent by fraction of total gas molecules in the controlled atmosphere.Specification, SA1097-PCT / 20250273. (Original) The OCXO integrated circuit device of claim 1 wherein:at least one of the electrical paths comprises a conductive surface trace; andthe controlled atmosphere comprises at least one of a hydrocarbon gas, an inorganic halide or an oxide, where the at least one of the hydrocarbon gas, the inorganic halide of the oxide makes up at least two percent by fraction of total gas molecules in the controlled atmosphere.

4. (Original) The OCXO integrated circuit device of claim 1 wherein:at least one of the electrical paths comprises a conductive surface trace; andthe controlled atmosphere comprises one of argon, xenon or krypton, where the at least one of the argon, the xenon orthe krypton makes up at least two percent by fraction of total gas molecules in the controlled atmosphere.

5. (Original) The OCXO integrated circuit device of claim 1 wherein:the interposer device comprises at least one of a glass, a polymer or a ceramic; andeach of the electrical paths directly abuts the at least one of the glass, the polymer or the ceramic, for at least a portion of an associated path length, and is sandwiched between the at least one of the glass, the polymer or the ceramic and a material having a thermal resistance of no less than 1000 K / W.

6. (Original) The OCXO integrated circuit device of claim 5 wherein the material comprises a layer of a solid material, the solid material thereby encapsulating the portion relative to the at least one of the glass, the polymer or the ceramic.

7. (Original) The OCXO integrated circuit device of claim 6 wherein the solid material comprises of at least one of a glass, a polymer or a ceramic, such that the portion is buried within at least one of a glass, a polymer or a ceramic.

8. (Original) The OCXO integrated circuit device of claim 1 wherein the resonator comprises a quartz crystal.

9. (Original) The OCXO integrated circuit device of claim 1 wherein:the OCXO integrated circuit device comprises a first die and a second die;the first die carries the resonator; andthe second die carries the processing circuit.Specification, SA1097-PCT / 202502710. (Original) The OCXO integrated circuit device of claim 9 wherein at least one of the first die or the second die is directly attached to the interposer device via at least one of a solder mount, a bonded conductive connection or a wire bond.

11. (Original) The OCXO integrated circuit device of claim 9 wherein each of the first die and the second die is directly mounted on the interposer device, and is in electrical communication with each of the electrical paths of the interposer device, via at least one of a solder mount, a bonded conductive connection or a wire bond.

12. (Original) The OCXO integrated circuit device of claim 9 wherein:the OCXO integrated circuit device also comprises a third die, the third die comprising a heating element, the first die being stacked with the third die in a manner that places the heating element and the resonator in thermal communication;the OCXO integrated circuit device also comprises a temperature sensor and a temperature control circuit; andthe electrical paths comprises a first electrical conductor, a second electrical conductor and a third electrical conductor, the first electrical conductor operable to carry the resonator signal in between the hot region and the cold region, the second electrical conductor operable to carry a temperature signal in between the hot region and the cold region, and the third electrical conductor operable to carry a control signal in between the hot region and the cold region.

13. (Original) The OCXO integrated circuit device of claim 12 wherein the first die is flip-chip mounted to the third die.

14. (Original) The OCXO integrated circuit device of claim 12 wherein the first die is directly interfaced with the third die by a thermally-conductive material that is not electrically-conductive.

15. (Original) The OCXO integrated circuit device of claim 12 wherein the resonator comprises a microelectromechanical systems (" MEMS") resonator.

16. (Original) The OCXO integrated circuit device of claim 15 wherein:the MEMS resonator is a first MEMS resonator;Specification, SA1097-PCT / 2025027the first die also supports a second MEMS resonator, the second MEMS resonator having a different variation in frequency as a function of operating temperature than the first MEMS resonator; the temperature sensor comprises the first MEMS resonator and the second MEMS resonator and the temperature control circuit is operable to identify a temperature as a function of a resonant frequency of the first MEMS resonator and as a function of a resonant frequency of the second MEMS resonator.

17. (Original) The OCXO integrated circuit device of claim 1 wherein:the processing circuit comprises a frequency correction circuit and the OCXO integrated circuit is operable to store at least one frequency correction value that is a function of the temperature; andthe frequency correction circuit is operable to receive a temperature indication, based on the temperature signal, and is operable to correct a frequency represented by the resonator signal, using the at least one frequency correction value, to generate the oscillation signal.

18. (Original) The OCXO integrated circuit device of claim 1 wherein:the OCXO integrated circuit device further comprises exterior electrical contacts; andthe OCXO integrated circuit device is operable to output the oscillation signal via one of the exterior electrical contacts.

19. (Original) The OCXO integrated circuit device of claim 18 wherein:the OCXO integrated circuit device further comprises digital storage and a programmable output frequency circuit and the processing circuit comprises at least one of a multiplier or a divider circuit;the OCXO integrated circuit is operable to receive a programmable value from an external source, via one of the exterior electrical contacts, and is to store the programmable value in the digital storage; andthe processing circuit is to adjust a frequency of the oscillation signal, dependent on the programmable value, using the at least one of the multiplier circuit or the divider circuit.

20. (Original) The OCXO integrated circuit device of claim 18 wherein the interposer device is electrically coupled through one of the base or the lid via a given one of a wire bond, a bonded conductive connection or a solderSpecification, SA1097-PCT / 2025027mount, and is operable to communicate the oscillation signal from the processing circuit to the one of the exterior electrical contacts via the given one.

21. (Original) The OCXO integrated circuit device of claim 1 wherein:the interposer device comprises a substantially flat panel having at least a layer of at least one of a glass, a polymer or a ceramic;the OCXO integrated circuit comprises a first die within the cavity;the substantially flat panel is mechanically mounted with respect to a first one of the base or the lid; the first die supports the resonator, the first die being mechanically mounted by the substantially flat panel, the mounting of the of the first die defining a flexible suspension; and the OCXO integrated circuit device is adapted to be mounted to an external, powered structure, the external, powered structure associated with a predetermined frequency of vibration associated with operation of the external, powered structure;the flexible suspension is structured so as to dampen transmission of a frequency that is between ten percent and thirty percent of the predetermined frequency of vibration.

22. (Original) The OCXO integrated circuit device of claim 1 wherein:the interposer device is configured to have at least one beam, and one or more associated bends or turns in beam direction;the OCXO integrated circuit comprises a first die, the cavity being defined between the base and the lid; the interposer device is mechanically mounted with respect to a first one of the base or the lid; the first die supports the resonator, the first die being mechanically mounted relative to the interposer device; andthe at least one beam and the one or more associated bends or turns in beam direction are structured so as to cause the interposer device to act as a phononic crystal that inhibits transmission of one or more vibrational frequencies between the resonator and first one of the base or the lid.Specification, SA1097-PCT / 2025027

Images