Cost-efficient core-shell parylene coating improving wire bond stiffness and damping

Abstract

A wire is bonded between a first surface and a second surface of an electronics package having a wire assembly. A core layer is applied to the wire to surround the wire, wherein the core layer has a first density. A shell layer is applied to the core layer to surround the core layer, wherein the shell layer has a second density. The first density is less than the second density.

Description

65HTE-510349-WO-2 (INT1025PCT) COST-EFFICIENT CORE-SHELL PARYLENE COATING IMPROVING WIRE BOND STIFFNESS AND DAMPING CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of an earlier filing date from U.S. Provisional Application Serial No.63 / 556,152, filed February 21, 2024. BACKGROUND

[0001] In the resource recovery industry, a drill string is used to drill a borehole in a formation. The drill string includes a drill bit for drilling into the formation and an electronics system that is used to control various aspects of the drilling operation. The electronic system is made up from multiple electronic modules. Wire bond interconnections are used for multiple applications inside the electronic package, e.g., to connect substrates or printed circuit boards to pins for making electrical connections to the tool-wiring and other electronic modules. As the drill bit rotates to drill the borehole, shocks and vibrations caused by drilling can be transmitted along the drill string. Exciting wire bonds at their eigenfrequencies reduces their lifetimes due to the high quality factors of these resonances. To increase the durability of the wire bonds, one can increase the stiffness of the bonds, reduce the amplitude of their oscillations (i.e., increasing their damping) or increase the local mechanical stability where fractures are typically found (e.g., at the wire bond heels). A single layer coating can be applied to protect a wire bond, increase its durability, and provide limited protection. Commonly, a thick coating would be required, driving manufacturing cost and time. Additional coatings of different coating materials can be used to tune the coating properties. However, complexity, manufacturing time and cost of the production process increase with each additional coating material. As both a conventional single coating and multi-layer coatings have drawbacks, there is a need for an alternative, cost-effective production process. SUMMARY

[0002] Disclosed herein is an electronics package including a wire assembly. The wire assembly includes a wire bonded between a first surface and a second surface, a core layer surrounding the wire, the core layer having a first density, and a shell layer surrounding the core layer. The shell layer has a second density, wherein the first density is less than the second density.65HTE-510349-WO-2 (INT1025PCT)

[0003] Also disclosed herein is a method of manufacturing an electronics package including a wire assembly. The method includes bonding a wire between a first surface and a second surface, applying a core layer to the wire to surround the wire, wherein the core layer has a first density, and applying a shell layer to the core layer to surround the core layer, wherein the shell layer has a second density, and wherein the first density is less than the second density. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

[0005] FIG.1 shows a drill string in an illustrative embodiment;

[0006] FIG.2 shows an electronics module usable at the downhole device of the drill string;

[0007] Figure 2A shows an interior cross-sectional view of the electronics module;

[0008] FIG.3 shows a side view of the bond wire;

[0009] FIG.4 shows a table of fundamental eigenfrequencies for different wire coating configurations;

[0010] FIG.5 shows a cross-sectional view of a core-shell coated wire in an embodiment;

[0011] FIG.6 shows a flowchart for a method of coating the wire; and

[0012] FIG.7 shows a deposition timeline for the core-shell layer of the wire. DETAILED DESCRIPTION

[0013] A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

[0014] Referring to FIG.1, a drilling system 100 including a drill string 102 is shown in an illustrative embodiment. While a land-based rig is shown, these concepts and the methods are equally applicable to offshore drilling systems. The drill string 102 can be suspended from a rig 104 and may include jointed tubulars 106 or coiled tubing for drilling a borehole 108 in a rock formation 110. The drill string 102 comprises an inner bore to flow a drilling fluid from the surface location 105 to a drill bit 112 at the bottom of the drill string 102 and back to the surface through an annulus between the wall of the borehole 108 and the drill string 102. The drill string 102 includes a bottomhole assembly (BHA) 114 uphole of65HTE-510349-WO-2 (INT1025PCT) the drill bit 112. In one configuration, the BHA 114 includes the drill bit 112 and a downhole tool. The downhole tool may be a sensor sub 116 a bidirectional telemetry device 118, a formation evaluation (FE) device 120, a steering unit 122 and rotary power devices such as drilling motors 124. The sensor sub 116 may include sensors for measuring near-bit direction (e.g., BHA azimuth and inclination, BHA coordinates, etc.) and sensors and tools for making rotary directional surveys. The drilling system 100 can also include information processing devices such as a surface controller 126 and / or a downhole controller 128. Communication between the surface location 105 and the BHA 114 can use uplinks and / or downlinks generated by a mud-driven telemetry device, such as a mud pulser and / or conveyed using hard wires (e.g., electrical conductors, fiber optics), acoustic signals, EM or RF. One or more electronics modules 130 incorporated into the BHA 114 or other component of the drill string 102 can include components as necessary to provide for data storage and processing, communication and / or control of the BHA 114. These components may be disposed in suitable compartments formed in or on the drill string 102. Exemplary electronics in the electronics module include printed circuit board assemblies (PCBA) and multiple chip modules (MCMs).

[0015] FIG.2 shows an electronics module 200 usable at the downhole device 106 of the drill string 100. The electronics module 200 includes a housing 202 and a pin section 204 through which a connection can be made to an external device. Figure 2A shows an interior cross-sectional view 210 of the electronics module 200. The housing 202 includes an electronics package 212 includes a substrate 214 and a die 216 attached to the substrate 214. The electronics package 212 can include a chip assembly or other electronics. A bond wire 218 forms a connection between the substrate 214 and a pin of the pin section 204 of the housing 202. A bond wire is typically made from gold, copper, silver, aluminum, or alloys, such as aluminum alloy. Another bond wire 220 can connect the substrate to a pin on the die 216. Although, only one bond wire 218 is shown connecting the substrate 214 to the pin section 204 of the housing 202, it is to be understood that multiple wires can be used for making multiple connections between the substrate 214 and pins of the pin section 204 of the housing 202. Additionally, there can be multiple bond wires 220 that connect from the substrate 214 to the die 216. The electronics module in FIG.2A can be a Multi Chip Module (MCM). MCMs use ceramic substrates to build the circuit board and comprise electronic components. Electronic components may be active or passive components. In embodiments electronic components may be built on or within the ceramic substrate. Electronics components are built from semi-conductor materials like silicon and / or germanium or65HTE-510349-WO-2 (INT1025PCT) alternative materials that are capable of surviving temperatures up to 150° C. to 175° C., 175° C. to 200° C., 200° C. to 225° C., 225° C. to 250° C., or 250° C. to 275° C. MCMs in high temperature applications may avoid using organic materials. Semiconductor components are often not soldered to the metallization of the ceramics substrate but interconnected by wire- bonding or using adhesives. Semiconductor component may be wire-bonded to the substrate as a so called “bare die”. Wire-bonding is a welding technique not using flux material. The coefficient of thermal expansion may be taken into account when selecting materials to build electronic components to be bonded to ceramic substrates. Electronic components are attached to at least one side of the ceramic substrate. In alternative embodiments, electronics components are attached to both sides of the ceramic substrate (front side and backside). MCMs are encapsulated in housings to protect the substrate as well as the electronics components from environments which may lead to degradation of materials used in MCMs (environmental gases, such as, for example, gases originating from organic materials used in potting material, solder, isolation material or polymer seals). The MCM housings are in many applications hermetically sealed by either closing the housing using welding technologies or sealing the housing by using metal seals. Electronics boards comprising circuit boards in downhole applications may reside in the downhole tool inside a cavity in a collar closed by a hatch cover or a sleeve. Alternatively, the circuit board may reside inside a container inside the inner bore of a downhole tool through which the drilling fluid travels downhole (probe-based downhole tool). Electronic boards (with or without housings) may be either fixedly connected inside the downhole tool (collar, container in inner bore (probe), mega frame) by using a fixation member, which may be a screw, an adhesive, or a clamp. The fixation may include a biasing member such as a spring or an elastomeric material which may be located somewhere inside the cavity in which the electronic board or electronic housing resides. The biasing member compensates for vibration and shocks generated during the downhole operation of the downhole tool.

[0016] FIG.3 shows a side view 300 of the bond wire 218. The bond wire 218 can be a cylindrical wire or a ribbon, in various embodiments. The bond wire 218 extends from point A at the pin section 204 (first surface) to point B at the substrate 214 (second surface) and forms an arc therebetween. Point A is located at a height h above point B. A horizontal distance between point A and point B is denoted by x. The vertical height of the wire hw is measured between point B and a top of the arc of the bond wire 218. The length of the bond wire 218 is denoted by lw. For illustrative purposes, the height h is 2.2 millimeters (mm), the horizontal distance x is 5.0 mm, the vertical height hwis 2.5 mm and the wire length lwis 5.865HTE-510349-WO-2 (INT1025PCT) mm. At the connection points A or B, the bond wire 218 is welded using common wire bonding techniques, such as ball bonding, wedge bonding, or compliant bonding. At each connection point. the wire bond forms a heel 222. A simulation of this band wire indicates that it has a resonance at a frequency of about 2.7 kHz (resonance frequency or eigenfrequency). No resonant excitation occurs at frequencies significantly less or more than this resonance frequency. The resonance frequency (~2.7 kHz) is within a frequency range of oscillations along the drill string 100, originating from the cutting process of the rock formation. The vibration may be high frequency torsional oscillations (HFTO) which are typically above of 50 Hz. Thus, the bond wire 218 is susceptible to rupture due to the vibrations in the drill string 100 that occur at or above (higher-order resonance modes) this resonance frequency. In an embodiment the resonance frequency of a bond wire may be between 1 kHz and 3 kHz, between 2 kHz and 5 kHz, or between 2 kHz and 10 kHz.

[0017] In various embodiments, a coating can be deposited on the bond wire 218 to shift an initial eigenfrequency of the bond wire 218 to a final eigenfrequency that is higher than the initial eigenfrequency and is outside of the range of vibration frequencies along the drill string 100. The coating can be made of parylene. The initial eigenfrequency or initial resonance frequency referred herein to the bond wire without any coating.

[0018] FIG.4 shows a table 400 of eigenfrequencies for different examples of bond wire coating configurations. The different coating configurations include a bond wire without any coating, a bond wire with a first coating layer (core layer), and a bond wire with the first layer (core layer) and a second layer (shell layer). These examples are given for demonstration purposes without limiting the generality of the approach. The frequencies in the table 400 are obtained from finite-element simulations for different bond wire coating configurations. The table 400 includes a first column 402 of eigenfrequencies (initial eigenfrequency) for a wire with no coating (uncoated bond wire), a second column 404 of eigenfrequencies for a bond wire with a coating having only a core layer, a third column 406 of eigenfrequencies for a shell layer without a wire and without a core layer, and a fourth column 408 of eigenfrequencies for a wire with a coating having both a core layer and a shell layer. The bond wire itself in this example has a density of 19.3 g / cm³ (gold), a Young’s modulus of 95 GigaPascals (GPa) and a Poisson ratio of 0.44. The core layer (second column 404) has a density of around 0.5 g / cm³ to 1.3 g / cm³. The shell layer (third column) has a density of 1.5 g / cm³ to 1.8 g / cm³. The material properties of the shell layer generally correspond to the material properties of a void-free Parylene with a density of 1.7 g / cm³, a Young’s modulus of 3.0 GPa and a Poisson ratio of 0.35. Again, these properties are65HTE-510349-WO-2 (INT1025PCT) examples only and are not limiting the approach to a specific type of bond wire coating material. The coating material may be Parylene F which is preferred for high temperature applications. In an alternative embodiment the coating material may be Parylene C or Parylene N. In one more embodiment the core layer may be made from Parylene C and the shell layer may be made from Parylene F. Parylene C is less expensive, but instable at high temperatures. However, covering the Parylene C core layer by a high temperature stable Parylene F shell layer protects the core layer from chemical reactions at elevated temperatures. Using a Parylene C core layer reduces cost of the bond wire assembly. In another embodiment, Polyurethane foam is used for the core layer and a Polyurethane finish is used for the shell layer. Other materials are feasible (e.g. silicone) as long as these are electrically non-conductive and layers with different densities can be applied to the bond wire. Combinations of material are in general possible as long as there are no undesired chemical reactions. This is the core layer is made from one material and the shell layer is made from a second material (e.g. core layer Parylene and shell layer a ceramic material or a metal (gold, aluminum)). In yet another embodiment a thin layer made from a third material is separating the core layer and the shell layer. The third material may be titanium oxide, zirconium oxide, or hafnium oxide. The third layer may be deposited on the second layer by Atomic Layer Deposition (ALD). The third layer has a higher density than the first layer.

[0019] In the first column 402, the eigenfrequency for the uncoated, 50 µm thick bond wire is about 2.7 kHz. In the second column 404, the eigenfrequency of a first oscillation mode for a bond wire coated with a 250 µm thick core layer of Parylene is about 12.5 kHz. The eigenfrequency of the first mode for a thin hollow Parylene shell layer or pipe (third column 406, 15 µm thickness of shell layer) with the same outer diameter (550 µm) as the configuration in column 404 and with the same length profile as the original bond wire is about 11.3 kHz. Both the 250 µm thick parylene core layer (404) and the thin parylene shell layer (406) raise the eigenfrequency of the respective oscillation mode to similar high values (i.e., 12.5 kHz and 11.3 kHz, respectively, for the first mode). The damping properties achieved using conventional methods are not optimized vs. the damping properties achieved using the methods disclosed herein. Hence, the core-shell coating disclosed herein reduces manufacturing time and provides superior damping. A conventional deposition rate for a void-free, high quality Parylene layer as used for the shell layer are 3 µm in 1 hour, or 5 µm in 1 hour, depending on the process parameters. For the core-shell configuration (fourth column 408), the core layer includes a 235 µm thick layer of parylene having a density lower than the layer of the shell layer and has numerous vacancies or voids. The core layer is65HTE-510349-WO-2 (INT1025PCT) deposited on the 50 µm thick bond wire by applying the coating at deposition rates well above the conventional deposition rates. The void-rich, low quality Parylene core layer can be deposited much faster than the high-quality shell layer. Typically, the deposition rate is twice to ten times a conventional deposition rate. In an embodiment, the deposition rate of the void-rich Parylene core layer may be 20 times a conventional deposition rate. The shell layer includes a conformal 15 µm thin Parylene coating layer and is deposited using deposition parameters suitable for achieving a layer that is substantially free of voids. For this simulation, the core layer has a density of 0.6 g / cm³, a Young’s modulus of 0.8 GPa and a Poisson ratio of 0.18. Because the core layer can be deposited quickly, the total deposition time for the core-shell configuration is less than the time needed to deposit a single layer coating having a same thickness as the core-shell configuration (thickness of core layer plus thickness of shell layer). The core, being void-rich and having a low-density, adds damping to excited oscillations (vibrations) of the bond wire. Thus, the eigenfrequency of the core- shell structure is found to be about 11.7 kHz (fourth column 408). The table in FIG.4 shows that a shift of the eigenfrequency to higher frequencies can be achieved by applying a thick layer (250 µm) of Parylene on the bond wire. The major increase in frequency shift is achieved by applying a core layer which adds mass to the wire and at the same time still allows flexibility due to the voids in the Parylene material, referred to in FIG.4 as “low density” layer. A void-free shell layer, referred to in FIG.4 as “full density” layer stabilizes the bond wire surrounded by the core layer. At the same time, the shell layer protects the bond wire from substances that may act detrimental. It can be observed that the shell layer does not have a big effect on the eigenfrequency shift. Parylene is applied to a bond wire commonly by vapor deposition with small deposition rates. Applying a sufficiently thick layer void-free Parylene to achieve the same shift of the eigenfrequency is economically not feasible. However, applying a void-rich Parylene layer allows much faster deposition rates, such as twice to twenty times faster than a void-free Parylene layer. The void-rich Parylene layer is not suited to provide to the bond wire the chemical isolation Parylene coatings are used for. Surrounding the thick void-rich core layer by a void-free thin Parylene layer provides the required chemical isolation. The combination of a bond wire surrounded by a core layer that is surrounded by a shell layer defines a bond wire assembly having a shifted eigenfrequency compared to the uncoated bond wire.

[0020] FIG.5 shows a cross-sectional view 500 of a core-shell coated wire in an embodiment. The coated wire includes a wire 502 (e.g., the bond wire 218), a first layer 504 of material surrounding the wire 502 and a second layer 506 of material surrounding the first65HTE-510349-WO-2 (INT1025PCT) layer 504. The first layer 504 and the second layer 506 form a core-shell structure with a flexible core and rigid shell. In an embodiment, the wire 502 has a diameter of about 50 micrometers (μm). The first layer 504 and the second layer 506 are made of parylene. The first layer 504 has a thickness d1 of about 235 μm. In another embodiment, the first layer 504 has a thickness in a range from about 40 μm to about 250 μm. In an embodiment, the first layer has a thickness in a range from about 50 μm to around 300 μm. In another embodiment, the first layer has a thickness in a range from about 100 μm to around 200 μm. The second layer 506 has a thickness d2 of about 1 μm to about 15 μm. In another embodiment, the second layer 506 has thickness in a range from about 5 μm to about 20 μm. In yet another embodiment, the second layer has a thickness in a range from about 1 μm to about 50 μm.

[0021] In an embodiment, the first layer 504 and the second layer 506 are formed by chemical vapor deposition of the parylene onto the wire 502. A parylene dimer is heated and the vapor cracks to produce a parylene monomer vapor which polymerizes during condensation on the target surface. To form the first layer 504, the parylene vapor is heated to a first temperature T1within a range of about 110º C to about 200º C at a pressure of about 20 Pascals. The first layer 504 is deposited at a first deposition rate which is a high deposition rate. Voids in the layer form during deposition at the first deposition rate. As a result, the first layer 504 has a void-rich foam-like structure. In an embodiment, the first layer 504 has a density of about 0.6 g / cm³ and is of a low stiffness due to its foam structure.

[0022] To form the second layer, the parylene source is heated to produce a parylene vapor at a second temperature T2that is lower than the first temperature and at a pressure of less than around 10 Pascals. The parylene is deposited on the first layer 504 at a second deposition rate that is less than the first deposition rate. Due to the slow deposition rate, the parylene deposits as a dense conformal film of high quality. The resulting second layer 506 thus forms a rigid shell having a high stiffness. The first layer 504 has a first density and the second layer 506 has a second density greater than the first density. The density of the first layer 504 is at least 30% less than the density of the second layer 506 (i.e., the density of the first layer is between 0% and 70% of the density of the second layer). In an embodiment, the density of the first layer is at least 20% less than the density of the second layer. In one more embodiment, the density of the first layer is at least 15% less than the density of the second layer. In yet another embodiment, the density of the first layer is at least 10% less than the density of the second layer

[0023] On its own (i.e., without the parylene coating), the wire has a first resonance frequency excited by a first range of vibration frequencies excited by the drilling process. In65HTE-510349-WO-2 (INT1025PCT) an embodiment the resonance frequency of a bond wire may be between 1 kHz and 3 kHz, between 2 kHz and 5 kHz, between 2 kHz and 10 kHz, or between 2 kHz and 20 kHz. The resonance frequency (eigenfrequency) may be the fundamental resonance frequency (fundamental eigenfrequency). The addition of the first layer (core layer) 504 dampens the amplitude of the excited oscillation mode and typically raises the resonance frequency of the bond wire from the first resonance frequency to a second resonance frequency greater than the first resonance frequency. The addition of the second layer (shell layer) 506 does not have much influence on the resonance frequency.

[0024] In other words, the eigenfrequency has a first value for a first wire assembly having only the wire 502, a second value for a second wire assembly having a combination of the wire 502 and the first layer 504, and a third value for a third wire assembly having a combination of the wire 502, the first layer 504 and the second layer 506. The second value is greater than the first value. In addition, the second and the third wire assembly has a greater stiffness than that of the first wire assembly and a greater tensile strength than that of the first wire assembly. Also, the second and the third wire assembly reduces strain at bond locations (heel) in comparison to the first wire assembly. The addition of the second layer (shell layer) 506 with a high first density material stabilizes (i.e., adds stiffness) and protects the bond wire covered by the first layer 504 with a second density that is smaller than the first density. The second layer 506 is stiffer than the first layer 504. The first layer 504 is flexible due to the void-rich structure. The flexibility of the first layer has a significant damping effect on the oscillation of the bond wire. The damping effect for a material is indicated by a quality factor of a resonance curve for the material. The quality factor of the bond wire without any coating, or of the bond wire with only a thick layer of conventional coating, is much greater than the quality factor of the bond wire with the applied core layer and shell layer. The dampening effect combined with the resonance frequency shift to higher frequencies and away from the range of typically exciting oscillations in downhole operations leads to reduced numbers of failures caused by ruptured bond wires. The damping effect as well as the resonance frequency shift is mainly achieved by the first layer 504. In an embodiment the bond wire assembly may only include the first layer 504. The main reason to apply the void-free second layer is the chemical protection of the bond wire, which may only be insufficiently provided by the first layer 504 due to the low quality Parylene. However, alternative measures may be possible to avoid chemical degradation of the bond wire, such as operation in a chemical isolated chamber. In this case the second layer 506 can be spared.65HTE-510349-WO-2 (INT1025PCT)

[0025] FIG.6 shows a flowchart 600 for a method of coating the wire. In box 602, the parylene dimer is heated to a first temperature T1. A cracker cracks the dimer to create a parylene monomer vapor at a first chamber pressure P1. In box 604, the parylene vapor is allowed to deposit and polymerize on the wire at a first deposition rate. In box 606, the parylene dimer is heated to a second temperature T2less than the first temperature to create a parylene monomer vapor at a second chamber pressure P2 that is less than the first chamber pressure P1. In box 608, the parylene deposits on the wire (i.e., on the core) at a second deposition rate that is less than the first deposition rate. Depositing the parylene onto the wire at the first deposition rate causes the parylene to be deposited at a lower density, thereby causing voids to form in the core layer. Depositing the parylene vapor onto the wire at the second rate causes deposition of a high density (i.e., a standard density of parylene coating) substantially without the formation of any voids (void-free). The result is that the shell layer is stiff relative to the core layer that is flexible.

[0026] FIG.7 shows a deposition timeline 700 for the core-shell layer of the wire. The layer is formed over a first deposition time t1with a first deposition rate R1and second deposition time t2 with a second deposition rate R2. The first layer 504 is formed during the first deposition time t1and the second layer 506 is formed during the second deposition time t2. The first deposition rate R1 is greater than the second deposition rate R2. During the first deposition time t1, the parylene dimer is heated to a high temperature T1, indicated by first deposition rate line 702. During the second deposition time t2, the parylene dimer is heated to a lower temperature T2(T1> T2), indicated by second deposition rate line 704. For comparison a third deposition time t3is shown which represents the time needed to deposit a layer with a thickness the same as the thickness of the core-shell coating using only deposition rate R2, as indicated by third deposition rate line 706 The third deposition time t3is longer than the sum of the first deposition time t1(during deposition occurs at rate R1) and the second deposition time t2(during which deposition occurs at rate R2).

[0027] Set forth below are some embodiments of the foregoing disclosure:

[0028] Embodiment 1. An electronics package including a wire assembly is disclosed. The wire assembly includes a wire bonded between a first surface and a second surface, a core layer surrounding the wire, the core layer having a first density, and a shell layer surrounding the core layer, the shell layer having a second density, wherein the first density is less than the second density.

[0029] Embodiment 2. The electronic package of any prior embodiment, wherein the core layer is made from a same material as the shell layer.65HTE-510349-WO-2 (INT1025PCT)

[0030] Embodiment 3. The electronic package of any prior embodiment, wherein the material is Parylene.

[0031] Embodiment 4. The electronic package of any prior embodiment, wherein the core layer is made from a first material and the shell layer is made from a second material, and the first material is different from the second material.

[0032] Embodiment 5. The electronic package of any prior embodiment, wherein the core layer is applied using vapor deposition at a first deposition rate and the shell layer is applied using vapor deposition at a second deposition rate, and wherein the first deposition rate is greater than the second deposition rate.

[0033] Embodiment 6. The electronic package of any prior embodiment, wherein the wire is part of a multi-chip module in a downhole tool.

[0034] Embodiment 7. The electronic package of any prior embodiment, wherein the wire has a first resonance frequency, and the wire surrounded by the core layer has a second resonance frequency, wherein the first resonance frequency is less than the second resonance frequency.

[0035] Embodiment 8. The electronic package of any prior embodiment, wherein the core layer has a first thickness and the shell layer has a second thickness, and the first thickness is greater than the second thickness.

[0036] Embodiment 9. The electronic package of any prior embodiment, wherein the first thickness is one of: (i) at least ten times greater than the second thickness; and least 5 times greater than the second thickness.

[0037] Embodiment 10. The electronic package of any prior embodiment, wherein the wire has a first resonance curve having a first quality factor and the wire assembly has a second resonance curve having a second quality factor, and the first quality factor is greater than the second quality factor.

[0038] Embodiment 11. The electronic package of any prior embodiment, wherein the first density is at least 10% less than the second density.

[0039] Embodiment 12. A method of manufacturing an electronics package including a wire assembly is disclosed. The method includes bonding a wire between a first surface and a second surface, applying a core layer to the wire to surround the wire, wherein the core layer has a first density, and applying a shell layer to the core layer to surround the core layer, wherein the shell layer has a second density, wherein the first density is less than the second density.65HTE-510349-WO-2 (INT1025PCT)

[0040] Embodiment 13. The method of any prior embodiment, wherein the core layer is made from a same material as the shell layer.

[0041] Embodiment 14. The method of any prior embodiment, wherein the material is Parylene.

[0042] Embodiment 15. The method of any prior embodiment, wherein the core layer is made from a first material and the shell layer is made from a second material, and the first material is different from the second material.

[0043] Embodiment 16. The method of any prior embodiment, further comprising applying the core layer using vapor deposition at a first deposition rate and applying the shell layer using vapor deposition at a second deposition rate, wherein the first deposition rate is greater than the second deposition rate.

[0044] Embodiment 17. The method of any prior embodiment, wherein the wire has a first resonance frequency, and the wire surrounded by the core layer has a second resonance frequency, wherein the first resonance frequency is less than the second resonance frequency.

[0045] Embodiment 18. The method of any prior embodiment, wherein the core layer has a first thickness and the shell layer has a second thickness, and the first thickness is greater than the second thickness.

[0046] Embodiment 19. The method of any prior embodiment, wherein the first thickness is one of: (i) at least ten times greater than the second thickness; and least 5 times greater than the second thickness.

[0047] Embodiment 20. The method of any prior embodiment, wherein the wire has a first resonance curve having a first quality factor and the wire assembly has a second resonance curve having a second quality factor, and the first quality factor is greater than the second quality factor.

[0048] Embodiment 21. The method of any prior embodiment, wherein the first density is at least 10% less than the second density.

[0049] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “about”, “substantially” and “generally” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and / or “substantially” and / or “generally” can include a range of ± 8% a given value.65HTE-510349-WO-2 (INT1025PCT)

[0050] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.

Claims

65HTE-510349-WO-2 (INT1025PCT) CLAIMS What is claimed is:

1. An electronics package including a wire assembly, the wire assembly comprising: a wire bonded between a first surface and a second surface; a core layer surrounding the wire, the core layer having a first density; and a shell layer surrounding the core layer, the shell layer having a second density, wherein the first density is less than the second density.

2. The electronic package of claim 1, wherein the core layer is made from a same material as the shell layer.

3. The electronic package of claim 2, wherein the material is Parylene.

4. The electronic package of claim 1, wherein the core layer is made from a first material and the shell layer is made from a second material, and the first material is different from the second material.

5. The electronic package of claim 1, wherein the core layer is applied using vapor deposition at a first deposition rate and the shell layer is applied using vapor deposition at a second deposition rate, and wherein the first deposition rate is greater than the second deposition rate.

6. The electronic package of claim 1, wherein the wire is part of a multi-chip module in a downhole tool.

7. The electronic package of claim 1, wherein the wire has a first resonance frequency, and the wire surrounded by the core layer has a second resonance frequency, wherein the first resonance frequency is less than the second resonance frequency.

8. The electronic package of claim 1, wherein the core layer has a first thickness and the shell layer has a second thickness, and the first thickness is greater than the second thickness.

9. The electronic package of claim 8, wherein the first thickness is one of: (i) at least ten times greater than the second thickness; and at least 5 times greater than the second thickness.

10. The electronic package of claim 1, wherein the wire has a first resonance curve having a first quality factor and the wire assembly has a second resonance curve having a second quality factor, and the first quality factor is greater than the second quality factor.

11. The electronic package of claim 1, wherein the first density is at least 10% less than the second density.65HTE-510349-WO-2 (INT1025PCT) 12. A method of manufacturing an electronics package including a wire assembly, comprising: bonding a wire between a first surface and a second surface; applying a core layer to the wire to surround the wire, wherein the core layer has a first density; and applying a shell layer to the core layer to surround the core layer, wherein the shell layer has a second density, wherein the first density is less than the second density.

13. The method of claim 12, wherein the core layer is made from a same material as the shell layer.

14. The method of claim 13, wherein the material is Parylene.

15. The method of claim 12, wherein the core layer is made from a first material and the shell layer is made from a second material, and the first material is different from the second material.

16. The method of claim 12, further comprising applying the core layer using vapor deposition at a first deposition rate and applying the shell layer using vapor deposition at a second deposition rate, wherein the first deposition rate is greater than the second deposition rate.

17. The method of claim 12, wherein the wire has a first resonance frequency, and the wire surrounded by the core layer has a second resonance frequency, wherein the first resonance frequency is less than the second resonance frequency.

18. The method of claim 12, wherein the core layer has a first thickness and the shell layer has a second thickness, and the first thickness is greater than the second thickness.

19. The method of claim 18, wherein the first thickness is one of: (i) at least ten times greater than the second thickness; and least 5 times greater than the second thickness.

20. The method of claim 12, wherein the wire has a first resonance curve having a first quality factor and the wire assembly has a second resonance curve having a second quality factor, and the first quality factor is greater than the second quality factor.

21. The method of claim 12, wherein the first density is at least 10% less than the second density.

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