Method for preventing epoxy resin exudation for biosensor device

Abstract

A fluid device and a method of preventing exudation of a spacer material in the fluid device are described herein. The fluid device includes a bulk acoustic resonator structure that defines at least one surface area region on which a functionalized material is disposed and the resonator structure includes a repulsion region. The fluid device further includes a spacer material that is disposed on the resonator structure and is disposed away from the at least one surface area region. The repulsion region is configured to prevent the spacer material from extending into the at least one surface area region. Additionally, an electronic board may be operatively attached to the resonator structure and the spacer material may be disposed in a gap between the electronic board and the resonator structure to electrically isolate electrical contacts and form a fluid channel.

Description

[0001] Related Applications

[0002] This application claims the benefit of priority to U.S. Provisional Application Serial No. 62 / 935,847, filed on November 15, 2019, the disclosure of which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure generally relates to sensor devices, such as bulk acoustic wave (BAW) sensor devices. In particular, the present disclosure relates to controlling the flow of isolation materials. Background Art

[0004] A biosensor (or biological sensor) is an analytical device that includes a biological element and a transducer that converts a biological response into an electrical signal. Certain biosensors involve a selective biochemical reaction between a specific binding material (e.g., an antibody, a receptor, a ligand, etc.) and a target substance (e.g., a molecule, a protein, DNA, vimentin, a bacterium, etc.), and the product of this highly specific reaction is converted by the transducer into a measurable quantity. Other sensors may utilize non-specific binding materials that are capable of binding to multiple types or classes of molecules or other portions that may be present in a sample. The term "functionalized material" may be used herein to generally refer to both specific and non-specific binding materials. The transduction methods used with biosensors may be based on various principles, such as electrochemical, optical, electrical, acoustic principles, etc. Among these, acoustic transduction offers many potential advantages, such as real-time, label-free, and low cost, and exhibits high sensitivity.

[0005] An acoustic wave device employs acoustic waves that propagate through or on the surface of a specific binding material, whereby any change in the characteristics of the propagation path affects the speed and / or amplitude of the wave. Acoustic wave devices are typically fabricated by microelectromechanical systems (MEMS) manufacturing techniques because of the need to provide microscale features suitable for enabling high-frequency operation. The presence of a functionalized material above or over the active region of the acoustic wave device permits an analyte to bind to the functionalized material, thereby changing the mass vibrated by the acoustic wave and changing the wave propagation characteristics (e.g., speed, thereby changing the resonant frequency). The change in speed can be monitored by measuring the frequency, amplitude-magnitude, and / or phase characteristics of the acoustic wave device and can be correlated with the physical quantity being measured.

[0006] Typically, BAW devices are fabricated by microelectromechanical systems (MEMS) manufacturing techniques because of the need to provide microscale features suitable for enabling high-frequency operation. In the context of biosensors, functionalized materials (e.g., specific binding materials; also referred to as bioactive probes or bioactive agents) can be deposited onto the sensor surface by various techniques such as microarray spotting (also referred to as microarray printing). Functionalized materials that provide non-specific binding utility (e.g., permitting binding of multiple types or classes of molecules) can also be used in certain contexts such as chemical sensing.

[0007] Existing processes for fabricating resonator arrays include many challenges. For example, epoxy resin is a bottom-fill material commonly used for encapsulating microelectronic components. However, since epoxy resin can become an adhesive with fillers, there is a known phenomenon called bleed-out associated with the use of epoxy resin. Bleed-out is essentially the separation of the various components of the adhesive due to differences in the surface energy of the substrate and the surface tension of the adhesive.

[0008] When epoxy resin is used as the bottom-fill for a BAW device, the epoxy resin may bleed out to undesirable locations on the BAW device. Typically, the epoxy resin can penetrate along the thin-film features of the device features, which can be described as dark line defects (DLDs). DLDs can pose problems for BAW devices because they can cause frequency shifts that can be detected by the sensor. The frequency shifts can be large and variable and can affect the performance of the BAW device.

[0009] Various techniques have been used to control bleed-out in the electronics packaging industry. For example, the epoxy resin formulation can be altered to adjust the surface tension and / or the substrate surface can be altered to adjust the surface energy. However, in some applications (e.g., due to qualification and biochemical requirements), it may be difficult to simply alter the epoxy resin formulation and / or the surface of the device. For example, in some applications, the top surface of the device can be functionalized by atomic layer deposition (ALD) of silicon dioxide (SiO2) and / or a specific epoxy resin may have an established history of compatibility with various assay solutions, and thus, changes to the top surface and / or the epoxy resin may increase risks and / or cause incompatibility issues. It may be desirable to provide a BAW device design that can prevent epoxy resin bleed-out, e.g., to avoid undesirable frequency shifts that may degrade the performance of the device. Summary of the Invention

[0010] The embodiments described herein may provide a BAW device that can prevent uncontrolled seepage or wicking of epoxy resin into undesired regions of the device (e.g., bioactive regions). For example, the BAW device may include a rejection region (e.g., a surface, layer, etc.) of the resonator structure or die that is configured to prevent epoxy resin from entering the rejection region. The rejection region may be positioned and oriented around at least a portion of the bioactive region such that epoxy resin cannot flow past the rejection region and interfere with the bioactive region. In other words, the rejection region can act as a barrier between the epoxy resin and the bioactive region. Thus, due to the rejection region, the device performance may not be degraded due to epoxy resin seepage.

[0011] Those skilled in the art will appreciate the scope of the present disclosure and recognize other aspects thereof after reading the following detailed description in conjunction with the accompanying drawings.

[0012] An illustrative fluid device may include a bulk acoustic wave resonator structure and an isolation material. The bulk acoustic wave resonator structure may define at least one surface area region on which a functionalized material is disposed, and the resonator structure may include a rejection region. The isolation material may be disposed on the resonator structure and disposed away from the at least one surface area region. The rejection region may be configured to prevent the isolation material from extending into the at least one surface area region.

[0013] In one or more embodiments, the fluid device may further include an electronic board attached to the resonator structure such that a gap is formed between the electronic board and the resonator structure. The isolation material may be disposed in at least a portion of the gap.

[0014] In one or more embodiments, the fluid device may further include electrical contacts operatively connecting the electronic board and the resonator structure. The isolation material may surround the electrical contacts to electrically isolate the electrical contacts from the external environment.

[0015] In one or more embodiments, the bulk acoustic wave resonator structure may include a surface layer and the rejection region is exposed through the surface layer.

[0016] In one or more embodiments, the rejection region may be located between the isolation material and the at least one surface area region.

[0017] In one or more embodiments, the fluid device may further include at least one wall extending away from the resonator structure and positioned adjacent to at least a portion of the at least one surface area region.

[0018] In one or more embodiments, the rejection region may surround the at least one wall.

[0019] In one or more embodiments, the bulk acoustic wave resonator structure may extend between a first end and a second end. A first portion of the isolation material may be disposed at the first end of the resonator structure, and a second portion of the isolation material may be disposed at the second end of the resonator structure such that the isolation material defines a fluid channel between the first portion and the second portion of the isolation material.

[0020] In one or more embodiments, the resonator structure may define a top surface. The rejection region may be recessed from the top surface.

[0021] In one or more embodiments, the rejection region may define a water contact angle greater than 40.

[0022] Additionally, an illustrative method of preventing seepage of an isolation material of a fluid device may include fabricating a bulk acoustic wave resonator structure. The bulk acoustic wave resonator structure may include a rejection region and may define at least one surface area region on which a functionalized material is disposed. The method may further include disposing an isolation material on the resonator structure and disposing it away from the at least one surface area region. Additionally, the method may include preventing the isolation material from extending into the at least one surface area region due to the rejection region.

[0023] In one or more embodiments, the method may further include attaching the bulk acoustic wave resonator structure to an electronic board such that a gap is formed between the resonator structure and the electronic board. The isolation material may be disposed in at least a portion of the gap.

[0024] In one or more embodiments, disposing the isolation material may include surrounding an electrical contact operably connected between the electronic board and the resonator structure to electrically isolate the electrical contact from the external environment.

[0025] In one or more embodiments, fabricating the bulk acoustic wave resonator structure may include etching a surface layer of the resonator structure to expose the rejection region.

[0026] In one or more embodiments, disposing the isolation material may include disposing a first portion of the isolation material at a first end of the resonator structure and disposing a second portion of the isolation material at a second end of the resonator structure.

[0027] In one or more embodiments, disposing the isolation material may further include forming a fluid channel between the first portion and the second portion of the isolation material.

[0028] In one or more embodiments, fabricating the bulk acoustic wave resonator structure can include forming at least one wall that extends from the resonator structure and is positioned adjacent to at least a portion of the at least one surface area region.

[0029] In one or more embodiments, fabricating the bulk acoustic wave resonator structure can include forming the exclusion zone to surround the at least one wall.

[0030] In one or more embodiments, the exclusion zone can define a water contact angle greater than 40.

[0031] In one or more embodiments, the exclusion zone can comprise a hydrophobic material.

[0032] The foregoing summary is not intended to describe every embodiment or every implementation. Rather, a more complete understanding of the illustrative embodiments will become apparent and appreciated by reference to the following detailed description and claims in view of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Exemplary embodiments will be further described with reference to the accompanying drawings, in which:

[0034] Figure 1 A perspective view of a bulk acoustic wave resonator structure from the prior art is shown.

[0035] Figure 2A Shows Figure 1 A top view of a bulk acoustic wave resonator structure of, which shows isolation material oozing into a region including a functionalized material.

[0036] Figure 2B Shows Figure 2A An enlarged perspective view of a bulk acoustic wave resonator structure of.

[0037] Figure 3 A top plan view of an illustrative bulk acoustic wave resonator structure in accordance with the present disclosure is shown.

[0038] Figure 4 Shows a Figure 3 Top plan view of a resonator structure including an isolation material disposed thereon.

[0039] Figure 5 Shows Figure 4 An isolated cross-sectional view of a resonator structure of.

[0040] Figure 6 An electronic board having electrical contacts is shown.

[0041] Figure 7 Shows Figure 3 A resonator structure of attached to Figure 6of the electronic board and includes a spacer material disposed therebetween.

[0042] Figure 8 shows Figure 7 the resonator structure and a bottom plan view of the electronic board.

[0043] Figure 9 shows Figure 7 the resonator structure and the electronic board and includes an adhesive disposed on the electronic board.

[0044] Figure 10 is shown relative to an illustrative cartridge body assembly Figure 7 the resonator structure and the electronic board.

[0045] Figure 11 shows a method of preventing seepage of the spacer material of a fluid device.

[0046] The drawings are presented primarily for clarity and are not necessarily drawn to scale. Additionally, various structures / components may be shown schematically or removed from some or all of the views to better illustrate aspects of the described embodiments, or where inclusion of such structures / components is not necessary for understanding the various exemplary embodiments described herein. However, the non - showing / description of such structures / components in a particular figure should not be construed as limiting the scope of the various embodiments in any way. Further, "Figure x" and "FIG. x" may be used interchangeably herein to refer to the figure numbered "x". DETAILED DESCRIPTION

[0047] In the following detailed description, several specific embodiments of devices, systems, and methods are disclosed. It should be understood that other embodiments may be conceived and formed without departing from the scope or spirit of the present disclosure. Reference is made to the drawings that form a part of the present disclosure. It should be understood that, of course, other embodiments may be conceived that are not described and / or shown herein. Accordingly, the following detailed description should not be taken in a limiting sense.

[0048] The present disclosure relates to bulk acoustic wave (BAW) devices and their use as biosensors. In particular, the present disclosure relates to devices containing bulk acoustic wave resonators, such as cartridges, and that can be used without sealing the sample orifice through which sample material is introduced into the cartridge. Alternatively, sample material can be introduced through the sample orifice and move through a passageway or channel due to capillary action or wicking. The sample material then binds to a functionalized material (e.g., a binding material) as it travels through the passageway or channel. As a result, the mass vibrating the BAW resonator changes and a change in the velocity of the acoustic wave device can be monitored to determine the physical quantity being measured (e.g., of the sample material).

[0049] Fabricating resonator arrays typically involves encapsulating microelectronic components using an epoxy resin as an underfill material. Specifically, the epoxy resin can be utilized to at least partially define fluid flow channels and / or electrically isolate electrical contacts. However, the epoxy resin may sometimes exude into various parts of the resonator in an undesirable manner. For example, epoxy resin exudation can interfere with signal feed lines, active regions, or functionalized materials and can cause large and variable offsets in the frequency measurement of the resonator (e.g., affecting the measurement accuracy of the resonator).

[0050] The embodiments described herein can prevent the uncontrolled exudation or wicking of epoxy resin into undesirable regions of the resonator device. For example, the resonator device can include a rejection region or a patterned thin-film feature of the resonator structure that creates a physical barrier for the epoxy resin. In other words, the rejection region prevents the epoxy resin from flowing into or through the rejection region and towards the bioactive region. The rejection region or the patterned thin-film feature of the resonator structure can take any suitable form, such as the surface or layer of the resonator structure or the thin-film feature. Additionally, the rejection region can be positioned and oriented in any suitable manner to prevent the epoxy resin from moving into the bioactive region. For example, the rejection region can be located around the entire perimeter of the bioactive region or can only be present at the location where the epoxy resin is disposed on the resonator. Additionally, in one or more embodiments, the rejection region can be a lower layer located beneath at least the surface layer of the resonator structure or die and exposed through the surface layer (e.g., by etching, a polymer photoresist mask, etc.).

[0051] In the following detailed description, several specific embodiments of composites, compositions, devices, systems, and methods are disclosed. It should be understood that other embodiments can be envisioned and formed without departing from the scope or spirit of the present disclosure. Therefore, the following detailed description should not be construed in a limiting sense.

[0052] Figure 1 A BAW resonator 20 of a fluid or bulk acoustic wave (BAW) device known in the art is shown. For example, the resonator 20 can define at least one surface area region 25 on which a functionalized material 24 is disposed. At least one surface area region 25 including the functionalized material 24 can be described as a bioactive region on which a sample material can bind to the functionalized material 24. Additionally, at least one surface area region 25 can be defined by the overlap of a first electrode and a second electrode with a piezoelectric material therebetween. An acoustic structure can be disposed above at least one surface area region 25. Specifically, Figure 1 The illustrated resonator 20 includes two surface area regions on the top surface 27 of the resonator 20.

[0053] The resonator 20 includes a mechanical contact 31 and an electrical contact 32 that project from the top surface 27 of the resonator 20. The mechanical contact 31 and the electrical contact 32 can be attached to an electronic board (not shown) and provide both a mechanical connection and an electrical connection between the resonator 20 and the electronic board. The resonator 20 also includes at least one wall 40 that is positioned between the electrical contact 32 and at least one surface area region 25. The at least one wall 40 extends along the top surface 27 of the resonator 20 and projects from the top surface. As Figure 1 shown, the resonator 20 includes two walls 40 that extend generally parallel to each other on opposite sides of at least one surface area region 25. Specifically, the inner wall 42 defines a middle portion that extends along a straight line and each end that extends inwardly, and the outer wall 41 extends along a straight line parallel to the middle portion of the inner wall 42.

[0054] In Figure 2A and Figure 2B are shown prior art resonators 20 having an isolation material 10 (e.g., epoxy resin) disposed thereon. The isolation material 10 is located above the mechanical contact 31 and the electrical contact 32 (shown in Figure 1 ) and on either side of at least one surface area region 25 (e.g., adjacent to the walls 40). As shown, the isolation material 10 surrounds the outer wall 41 and extends toward the inner wall 42 (on both sides). Additionally, the isolation material 10 exudes or wicks 15 along the inner wall 42 and other electrical components within at least one surface area region 25. In other words, the isolation material 10 adheres to the edges and interfaces (e.g., between the top surface 27, the walls 40, the photoimageable epoxy resin, etc.) and extends along the edges and interfaces to “creep” into at least one surface area region 25. This exuding or wicking 15 of the isolation material 10 can be described as a dark line defect that can affect the operation of the resonator 20 in an undesirable manner (e.g., causing variability in frequency measurements).

[0055] In Figure 3 is shown a bulk acoustic wave (BAW) resonator structure 120 according to the present disclosure (e.g., of a fluid sensor device). Substrate materials suitable for the device can include silicon, alumina, sapphire, or another semiconductor material. In one or more embodiments, the resonator structure 120 can be described as a die. The resonator structure 120 can define at least one surface area region 125 having a functionalized material 124 disposed thereon (e.g., similar to the resonator 20 described with respect to Figure 1 ). In other words, at least one surface area region 125 can include a bioactive zone on which a sample material can bind to the functionalized material 124. It should be noted that in some embodiments, at least one surface area region 125 may not include the functionalized material 124 (e.g., if the surface area region 125 is configured to be used as a control).

[0056] At least one surface area region 125 may define any suitable size and / or shape on the top surface 127 of the resonator structure 120. Additionally, the resonator structure 120 may include any number of suitable surface area regions 125. For example, Figure 3 the illustrated resonator structure 120 includes two surface area regions 125 (e.g., each of which may have the same, different functionalized materials or no functionalized material). In other embodiments, the resonator structure 120 may have one, three, four, five, etc. surface area regions 125 disposed on a single die 120.

[0057] The resonator structure 120 may include mechanical contacts 131 and electrical contacts 132 that project from the top surface 127 of the resonator structure 120. At least one of the electrical contacts 132 may be operatively coupled to an acoustic sensor at a bioactive region within at least one surface area region 125. Additionally, the electrical contacts 132 may be operatively coupled to an electronic board 150 (e.g., as Figure 6 illustrated), such that a frequency signal from at least one resonator of the resonator structure 120 can be transmitted to the electronic board 150. The electrical contacts 132 may include any suitable bump material, such as copper pillars with tin (e.g., formed from any suitable bump material). Similarly, any number of suitable mechanical contacts 131 and electrical contacts 132 may be present. For example, as Figure 3 illustrated, there are four electrical contacts 132 near the first end 121 of the resonator structure 120 and four mechanical contacts 131 near the second end 122 of the resonator structure 120. Specifically, there may be at least two electrical contacts 132 associated with each of at least one surface area region 125.

[0058] The resonator structure 120 may further include at least one wall 140 that extends along and projects from the resonator structure 120. For example, at least one wall 140 may be positioned between at least one surface area region 125 and the mechanical contacts 131 or electrical contacts 132. The resonator structure 120 may include any suitable number of walls 140. For example, as Figure 3 illustrated, the resonator structure 120 may include two walls 140 that extend generally parallel to each other on opposite sides of at least one surface area region 125 (e.g., near the first end 121 and the second end 122). In other embodiments, the resonator structure 120 may include one wall or more than two walls on either side of at least one surface area region 125. Additionally, at least one wall 140 may define any suitable shape. For example, as Figure 3As shown, at least one wall 140 may define an elongated shape extending between sides of the resonator structure 120. In other embodiments, at least one wall 140 may define a shape that completely surrounds at least one surface area region 125 (e.g., a continuous or discontinuous wall that always surrounds at least one surface area region 125). Similarly, as Figure 3 shown, at least one wall 140 may include: an inner wall 142 that defines a middle portion extending along a straight line and each end that extends inwardly (e.g., toward at least one surface area region 125); and an outer wall 141 that extends along a straight line parallel to the middle portion of the inner wall 142.

[0059] Furthermore, at least one wall 140 may define any suitable width, length, and height. For example, at least one wall 140 may define the following widths: about greater than or equal to 10 microns, greater than or equal to 15 microns, greater than or equal to 20 microns, etc. and / or less than or equal to 40 microns, less than or equal to 30 microns, less than or equal to 25 microns, etc. Additionally, for example, at least one wall 140 may define the following lengths: about greater than or equal to 500 microns, greater than or equal to 750 microns, greater than or equal to 1000 microns, etc. and / or less than or equal to 2000 microns, less than or equal to 1500 microns, less than or equal to 1250 microns, etc. Additionally, for example, at least one wall 140 may define the following heights: about greater than or equal to 10 microns, greater than or equal to 15 microns, greater than or equal to 20 microns, etc. and / or less than or equal to 40 microns, less than or equal to 30 microns, less than or equal to 25 microns, etc. At least one wall 140 may comprise any suitable material (e.g., formed of any suitable material). For example, at least one wall 140 may comprise a photoimageable epoxy, a photoimageable solder mask, a photoimageable dry film photoresist, etc. In one or more embodiments, at least one wall 140 may comprise a dry film type photoimageable epoxy supplied by Tokyo Ohka Kogyo called .

[0060] At least one wall 140 may be positioned to assist in restricting an isolation material disposed on the resonator structure (e.g., disposed close to the electrical contact 132) from extending into at least one surface area region 125. However, as described herein with respect to Figure 2A and Figure 2B at least one wall 140 alone may not be able to completely prevent the isolation material from oozing into at least one surface area region 125.

[0061] The resonator structure 120 may include a rejection region 130 configured to prevent an encapsulation material (e.g., an adhesive for underfill epoxy) from extending into at least one surface area region 125 and disrupting the operation of the BAW device. As described herein, the rejection region 130 may include any portion (e.g., layer, surface, etc.) of the resonator structure 120 that rejects the encapsulation material. Thus, the rejection region 130 may be located at any suitable location between the at least one surface area region 125 and a location where the encapsulation material may be disposed on the resonator structure 120 (e.g., the encapsulation material may be disposed adjacent to the first end 121 and the second end 122 of the resonator structure 120). For example, as Figure 4 and Figure 5 shown, the rejection region 130 may form a barrier or boundary for the encapsulation material 110, e.g., to prevent the encapsulation material 110 from entering the at least one surface area region 125. Thus, the rejection region 130 may be located between the electrical contact 132 (e.g., since the encapsulation material 110 may be disposed above the electrical contact 132) and the at least one surface area region 125.

[0062] As Figure 3 shown, the rejection region 130 includes two separate portions or zones. For example, a first portion 134 may be closer to the first end 121 of the resonator structure 120 and extend between the sides of the resonator structure 120, while a second portion 136 may be closer to the second end 122 of the resonator structure 120 and extend between the sides of the resonator structure 120. The resonator structure 120 may include any number of different portions of the rejection region 130. For example, the resonator structure 120 may include one portion or more than two portions of the rejection region 130. Additionally, in one or more embodiments, the rejection region 130 may define a shape that completely surrounds the at least one surface area region 125 (e.g., a continuous or discontinuous rejection region 130 that always surrounds the at least one surface area region 125). For example, the rejection region 130 may define a square shape, a circular shape, an oval shape, etc., around the at least one surface area region 125. In one or more embodiments, the rejection region 130 may define a continuous path that always surrounds the at least one surface area region 125 such that an inner region (e.g., including the at least one surface area region 125) is defined and an outer region (e.g., including the electrical contact 132) is defined, and the rejection region 130 completely separates the inner region from the outer region.

[0063] Additionally, as Figure 3As shown, the exclusion zone 130 completely surrounds at least one wall 140 (e.g., each portion of the exclusion zone 130 completely surrounds a pair of walls 140). In one or more embodiments, the exclusion zone 130 may overlap with a portion of at least one wall 140 or may be completely separated from at least one wall 140. In other embodiments, the resonator structure 120 may not include any walls 140 (e.g., within the exclusion zone 130) and may include only the exclusion zone 130 to prevent the isolation material 110 from extending into at least one surface area region 125.

[0064] The exclusion zone 130 of the resonator structure 120 or die may take any suitable form that restricts the extension of the isolation material 110 through the exclusion zone 130. In other words, the isolation material 110 can be prevented from entering at least one surface area region 125 without changing the composition of the top surface 127 of the resonator structure 120 and / or the formulation of the isolation material 110 (e.g., due to the exclusion zone 130). As Figure 5 shown, the exclusion zone 130 may be recessed from the top surface 127 of the resonator structure 120 (e.g., the exclusion zone 130 may be a subsurface layer). For example, the exclusion zone 130 may be recessed from the top surface 127 by about greater than or equal to 50 angstroms, greater than or equal to 500 angstroms, greater than or equal to 1,000 angstroms, etc. and / or less than or equal to 2 microns, less than or equal to 1 micron, less than or equal to 5,000 angstroms, etc. In other words, the resonator structure 120 may include a surface layer 126 deposited on top of the exclusion zone 130, and the underlying layer forming the exclusion zone 130 may be exposed through the surface layer 126. For example, a photoresist mask may define an opening in the layer exposing the exclusion zone 130 and / or further processing using pre-sputter etching may remove the surface layer 126 and expose the layer defining the exclusion zone 130. In other embodiments, the exclusion zone 130 may include a surface treatment positioned on the top surface 127 of the surface layer 126.

[0065] The surface layer 126 of the resonator structure or die may comprise a material different from the exclusion zone 130 as each may be optimized for different purposes. For example, the surface layer 126 may comprise a silicon material such as silicon nitride, silicon dioxide, etc. (e.g., formed of a silicon material). The particular material of the surface layer 126 may be used due to manufacturing and / or compatibility reasons (e.g., for use with sample materials) and may therefore not be easily modified. Additionally, the material of the surface layer 126 (e.g., silicon nitride, silicon dioxide, etc.) may not prevent the movement of the isolation material 110. On the other hand, the exclusion zone 130 may be optimized to prevent or restrict the flow of the isolation material 110. For example, the exclusion zone 130 may comprise any suitable material that repels the isolation material 110 in any suitable manner (e.g., formed of any suitable material).

[0066] In one or more embodiments, the repulsion zone 130 may comprise any material that defines a low surface energy to, for example, repel the isolation material 110 and / or prevent the isolation material 110 from oozing out. For example, the surface energy of the portion of the isolation material 110 on the surface of the resonator structure 120 (e.g., the repulsion zone 130) may be lower than the surface energy of the surface layer 126. The surface energy of the repulsion zone 130 can be determined in any suitable manner. Thus, the low surface energy repulsion zone 130 can prevent the isolation material 110 from wicking or oozing into undesired locations on the resonator structure 120.

[0067] In one or more embodiments, the water contact angle measurement can be a good indicator of surface energy. For example, a high water contact angle indicates a lower surface energy, while a low water contact angle indicates a high surface energy. Thus, the repulsion zone 130 may have a high water contact angle, such as a water contact angle of 40 or greater. In some embodiments, the repulsion zone 130 may have a water contact angle of 50 or greater or 60 or greater. The water contact angle can be measured in any suitable manner, such as using a contact angle goniometer. Thus, the water contact angle of the repulsion zone 130 can indicate that the repulsion zone 130 restricts or prevents the movement of the isolation material 110. Additionally, Table 1 shown below shows that Al2O3 (e.g., the material of the repulsion zone 130) can be more hydrophobic than SiO2 (e.g., the material of the surface layer 126). Table 1 shows that the water contact angle of Al2O3 decreases after 20 seconds of pre-sputter etching (PSE). For example, argon pre-sputter etching is a surface removal technique used to clean the surface. Additionally, Table 1 shows that the water contact angle of Al2O3 can increase to a value higher than the initially as-deposited water contact angle of Al2O3 after treatment in a chemical that etches Al2O3, such as a dilute tetramethylammonium hydroxide (TMAH) solution. Etching Al2O3 exposes the original Al2O3, which increases the water contact angle.

[0068]

[0069] Table 1 - Water Contact Angle

[0070] In one or more embodiments, the repulsion zone 130 may comprise a hydrophobic material, such as an Al2O3 fluorinated surface produced by etching the surface with SF6; for example, an aluminum or aluminum oxide film etched with SF6 can produce a fluorine-rich hydrophobic surface. Additionally, the repulsion zone 130 may further include the deposition and patterning of fluorinated materials such as photoimageable polyimide, resist, etc. In other words, the repulsion zone 130 can take various different forms to prevent the movement of the isolation material 110 (e.g., restrict the movement to at least one surface area region 125). Forming the repulsion zone with a fluorine-rich surface creates a waterproof, and thus low surface energy surface that results in a high water contact angle.

[0071] As Figure 4As shown, the isolation material 110 can be disposed on the resonator structure 120 away from at least one surface area region 125. For example, the isolation material 110 can be disposed in two separate portions located near the first end 121 and the second end 122 of the resonator structure 120 such that at least one surface area region 125 can be located between the portions of the isolation material 110. As described herein, the exclusion region 130 can be positioned and configured to prevent the isolation material 110 from extending into at least one surface area region 125. For example, as Figure 4 and Figure 5 shown, the isolation material 110 terminates at the exclusion region 130 such that the exclusion region 130 serves as a boundary or barrier. Specifically, the wicking of the isolation material 110 can terminate at the boundary of an opening exposing the exclusion region 130.

[0072] In one or more embodiments, the isolation material 110 can be disposed on the resonator structure 120 to cover and surround the mechanical contact 131 and the electrical contact 132 (e.g., Figure 3 the contacts 131, 132 shown). For example, the isolation material 110 can surround the electrical contact 132 to electrically isolate the electrical contact 132 from the external environment (e.g., to prevent fluid or moisture from interacting with the electrical contact 132). In other words, the isolation material 110 can form a fluid seal in the region or zone of the electrical contact 132. Additionally, in one or more embodiments, the isolation material 110 can be disposed on the resonator structure 120 in separate portions to define a fluid channel between the separate portions. For example, as Figure 4 shown, a first portion 111 of the isolation material 110 (e.g., near the first end 121) and a second portion 112 of the isolation material 110 (e.g., near the second end 122) can help define a fluid channel 114 therebetween. The fluid channel 114 can define a fluid flow path of the resonator structure 120 such that sample material can pass through at least one surface area region 125 positioned along the fluid flow path (e.g., to bind to the functionalized material 124).

[0073] The isolation material 110 can comprise any suitable underfill material (e.g., formed of any suitable underfill material). For example, the isolation material 110 can comprise a thermally curable liquid epoxy resin or a rapidly curable liquid epoxy resin, etc. Different types of materials for forming the exclusion region 130 can interact with the material of the isolation material 110 such that the isolation material 110 may not be able to pass through the exclusion region 130.

[0074] The resonator structure 120 can be attached to an electronic board 150 (e.g., as Figure 6 shown) to produce a fluid sensor device 100. The electronic board 150 (e.g., a laminate) can define a top surface 151 and a bottom surface 152 (e.g., as Figure 8as shown). The electronic board 150 may include mechanical contacts 153 (e.g., shown in Figure 3 ), and electrical contacts 154 (e.g., shown in Figure 3 ), that are positioned to be operatively coupled to the resonator structure 120, respectively. The electronic board 150 may also define an opening 156 that extends between a top surface 151 and a bottom surface 152 and helps to form a fluid channel 114 through which sample material flows. For example, the opening 156 of the electronic board 150 may define an elongated shape and extend between a first opening end 161 and a second opening end 162.

[0075] As Figure 7 shown, the resonator structure 120 may be attached to the electronic board 150. For example, the resonator structure 120 may be operatively coupled to the electronic board 150 (e.g., by attaching the mechanical contact 131 and the electrical contact 132 to the mechanical contact 153 and the electrical contact 154, respectively), such that the top surface 151 of the electronic board 150 faces the top surface 127 of the resonator structure 120. In other words, the bottom surface 137 of the resonator structure 120 is visible in Figure 7 . Mounting the resonator structure 120 to the electronic board 150 may be described as flip-chip bonding because the top surface 127 is "flipped" and bonded to the electronic board 150. Additionally, as Figure 8 shown, the top surface 127 (including at least one surface area region 125) of the resonator structure 120 may be visible through the opening 156 of the electronic board 150. Thus, the resonator structure 120 may bridge the opening 156 such that at least one surface area region 125 may be positioned along the elongated shape of the opening 156 (e.g., positioned between the first opening end 161 and the second opening end 162).

[0076] When the resonator structure 120 is operatively coupled to the electronic board 150, a gap may be formed therebetween (e.g., due to the columnar shape of the mechanical contact 131 and the electrical contact 132). In other words, when coupled together, the top surface 151 of the electronic board 150 may be spaced apart from the top surface 127 of the resonator structure 120. The isolation material 110 may be disposed within the gap between the resonator structure 120 and the electronic board 150. Specifically, the isolation material 110 (e.g., by a method of needle dispensing or spraying adjacent to the gap between the resonator structure 120 and the electronic board 150) may wick between the resonator structure 120 and the electronic board 150. Additionally, as described herein, the resonator structure 120 may be operatively coupled to the electronic board 150 on either side of the opening 156 of the electronic board 150 (e.g., due to the mechanical contact 131 and the electrical contact 132). The isolation material 110 may be disposed within the gap between the resonator structure 120 and the electronic board 150 on each coupled side. For example, a first portion 111 of the isolation material 110 may be disposed proximate the first end 121 of the resonator structure 120, and a second portion 112 of the isolation material 110 may be disposed proximate the second end 122 of the resonator structure 120. Due to the exclusion zone 130 of the resonator structure 120, the isolation material 110 may be confined to each end of the resonator structure 120. Thus, the isolation material 110 may be disposed (e.g., on either end of the resonator structure 120) within at least a portion of the gap between the resonator structure 120 and the electronic board 150, but not within at least one surface area region 125.

[0077] Figure 9 Additional components of the fluid device 100 that form the fluid channel 114 together with the resonator structure 120 and the electronic board 150 are shown. For example, the fluid device 100 may include a first adhesive film 104 or patch attached to the bottom surface 152 of the electronic board 150. The first adhesive film 104 may form the surface (e.g., the bottom surface) of the fluid channel 114 within the opening 156 of the electronic board 150. The first adhesive film 104 may define a solid sheet.

[0078] Additionally, the fluid device 100 may include a second adhesive film 106 or patch attached to the top surface 151 of the electronic board 150. The second adhesive film 106 may form the fluid channel 114 within the opening 156 of the electronic board 150 (e.g., as Figure 4The surface (e.g., the upper surface) as shown. In one or more embodiments, the second adhesive film 106 may include a cutout 105 that accommodates the resonator structure 120. Additionally, the second adhesive film 106 may define a first fluid port 107 and a second fluid port 108 on either side of the resonator structure 120. When the second adhesive film 106 is attached to the electronic board 150, the first fluid port 107 and the second fluid port 108 may be aligned with the first open end 161 and the second open end 162 respectively (e.g., as Figure 6 shown). Additionally, the first fluid port 107 and the second fluid port 108 may be configured such that a sample material can be deposited onto the fluid channel 114 through one of the first fluid port 107 and the second fluid port 108, pass through the fluid channel 114 (and e.g., through the bioactive region), and exit the fluid channel 114 through the other of the first fluid port 107 and the second fluid port 108.

[0079] The first adhesive film 104 and the second adhesive film 106 may comprise any suitable material, such as a pressure-sensitive adhesive on a polymer substrate etc. (e.g., formed of any suitable material). Additionally, the first adhesive film 104 and the second adhesive film 106 may define a property that facilitates the wicking or capillary action of the sample material, such that, for example, the sample material passes through at least one surface area region 125.

[0080] Figure 10 The resonator structure 120 and the electronic board 150 are shown relative to other components of the fluid device 100. For example, the fluid device 100 may include a cartridge body 170 within which the electronic board 150 is positioned; and a turntable assembly 172 positioned relative to the cartridge body.

[0081] In Figure 11An illustrative method 200 for preventing seepage of a spacer material of a fluid device is shown. Method 200 may include fabricating 210 a bulk acoustic wave (BAW) resonator structure that includes a rejection zone and defines at least one surface area region on which a functionalized material is disposed. The resonator structure may be configured to receive a sample material and measure different frequency shifts based on the degree of binding of the sample material to the functionalized material. Method 200 may further include disposing 220 the spacer material on the resonator structure and disposing it away from at least one surface area region. Disposing 220 the spacer material may include forming a fluid channel between multiple portions of the spacer material (e.g., a first portion of the spacer material proximate a first end of the resonator structure and a second portion of the spacer material proximate a second end of the resonator structure). Additionally, disposing 220 the spacer material may include surrounding an electrical contact operably coupled between an electronic board and the resonator structure to electrically isolate the electrical contact from the external environment (e.g., any moisture or fluid from the fluid channel). Method 200 may further include preventing 230 the spacer material from extending into at least one surface area region due to the rejection zone.

[0082] In one or more embodiments, fabricating 210 the resonator structure may include etching a surface layer of the resonator structure to expose the rejection zone (e.g., using a polymer photoresist mask). In one or more embodiments, method 200 may further include attaching the resonator structure to an electronic board such that a gap is formed between the resonator structure and the electronic board, e.g., such that the spacer material can be disposed therebetween. In one or more embodiments, fabricating 210 the resonator structure may include forming at least one wall that extends from the resonator structure and is positioned adjacent to at least a portion of at least one surface area region. Additionally, in one or more embodiments, fabricating 210 the resonator structure may include forming the rejection zone to surround at least one wall.

[0083] Illustrative embodiments have been described and reference has been made to possible variations of those embodiments. Those skilled in the art will appreciate these and other variations, combinations, and modifications, and it should be understood that the claims are not limited to the illustrative embodiments set forth herein.

[0084] Unless otherwise indicated, all scientific and technical terms used herein have the meanings commonly used in the art. The definitions provided herein will assist in the understanding of certain terms frequently used herein and are not meant to limit the scope of the present disclosure.

[0085] Unless the context clearly indicates otherwise, as used in this specification and the appended claims, the singular forms "a / an" and "the" cover embodiments having plural referents. Unless the context clearly indicates otherwise, as used in this specification and the appended claims, the term "or" is generally employed in its sense including "and / or". The term "and / or" means one or all of the recited elements or any combination of two or more of the recited elements.

[0086] As used herein, "have", "having", "include", "including", "comprise", "comprising", etc. are used in their open-ended sense and generally mean "including but not limited to". It should be understood that "consisting essentially of", "consisting of", etc. are subsumed under "comprising", etc. As used herein, "consisting essentially of" when referring to a composition, product, method, etc. means that the components of the composition, product, method, etc. are limited to the recited components and any other components that do not materially affect one or more of the basic and novel characteristics of the composition, product, method, etc.

[0087] The terms "preferred" and "preferably" refer to embodiments of the present invention that may provide certain benefits in certain circumstances. However, in the same or other circumstances, other embodiments may also be preferred. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the present disclosure including the claims.

[0088] Additionally, in this document, a numerical range recited by endpoints includes all the values contained within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc., or 10 or less includes 10, 9.4, 7.6, 5, 4.3, 2.9, 1.62, 0.3, etc.). In the case of a value range "up to" a particular value, that value is included within the said range.

[0089] Any directions mentioned herein, such as "top", "bottom", "left", "right", "up", "down", and other directions and orientations are described herein for the purpose of clearly referring to the accompanying drawings and are not restrictive of the actual device or system or the use of the device or system. The device or system described herein can be used in multiple directions and orientations.

Claims

1. A fluid device, the fluid device comprising: a bulk acoustic wave resonator structure that defines at least one surface area region having a functionalized material disposed thereon, and wherein the resonator structure includes a repulsion region and a surface layer formed on at least a portion of the resonator structure; and a spacer material disposed on the surface layer and disposed away from the at least one surface area region, wherein the repulsion region is configured to prevent the spacer material from extending into the at least one surface area region, and wherein the water contact angle of the repulsion region is higher than the water contact angle of the surface layer.

2. The fluid device according to claim 1, the fluid device further comprising an electronic board attached to the resonator structure such that a gap is formed between the electronic board and the resonator structure, wherein the spacer material is disposed in at least a portion of the gap.

3. The fluid device according to claim 2, the fluid device further comprising an electrical contact operably connecting the electronic board and the resonator structure, wherein the spacer material surrounds the electrical contact to electrically isolate the electrical contact from the external environment.

4. The fluid device according to any one of the preceding claims, wherein the repulsion region is exposed through an opening in the surface layer.

5. The fluid device according to claim 1, wherein the repulsion region is located between the spacer material and the at least one surface area region.

6. The fluid device according to claim 1, the fluid device further comprising at least one wall extending away from the resonator structure and positioned adjacent to at least a portion of the at least one surface area region.

7. The fluid device according to claim 6, wherein the repulsion region surrounds the at least one wall.

8. The fluid device according to claim 1, wherein the bulk acoustic wave resonator structure extends between a first end and a second end, wherein a first portion of the spacer material is disposed at the first end of the resonator structure and a second portion of the spacer material is disposed at the second end of the resonator structure such that the spacer material defines a fluid channel between the first portion and the second portion of the spacer material.

9. The fluid device according to claim 1, wherein the resonator structure defines a top surface, and wherein the repulsion region is recessed from the top surface.

10. The fluid device according to claim 1, wherein the repulsion region defines a water contact angle greater than 40.

11. A method of preventing spacer material from oozing out of a fluid device, the method comprising: fabricating a bulk acoustic wave resonator structure that includes a repulsion region and a surface layer formed on at least a portion of the resonator structure and defines at least one surface area region having a functionalized material disposed thereon; and An isolation material is disposed on the surface layer and is disposed away from the at least one surface area region, wherein the repulsion region prevents the isolation material from extending into the at least one surface area region, and wherein the water contact angle of the repulsion region is higher than the water contact angle of the surface layer, thereby preventing the isolation material of the fluid device from oozing out.

12. The method of claim 11, the method further comprising attaching the bulk acoustic wave resonator structure to an electronic board such that a gap is formed between the resonator structure and the electronic board, wherein the isolation material is disposed in at least a portion of the gap.

13. The method of claim 12, wherein disposing the isolation material includes surrounding an electrical contact operably connected between the electronic board and the resonator structure to electrically isolate the electrical contact from the external environment.

14. The method of any one of claims 11 to 13, wherein manufacturing the bulk acoustic wave resonator structure includes etching the surface layer of the resonator structure to expose the repulsion region.

15. The method of claim 11, wherein disposing the isolation material includes disposing a first portion of the isolation material at a first end of the resonator structure and disposing a second portion of the isolation material at a second end of the resonator structure.

16. The method of claim 15, wherein disposing the isolation material further includes forming a fluid channel between the first portion and the second portion of the isolation material.

17. The method of claim 11, wherein manufacturing the bulk acoustic wave resonator structure includes forming at least one wall that extends from the resonator structure and is positioned adjacent to at least a portion of the at least one surface area region.

18. The method of claim 17, wherein manufacturing the bulk acoustic wave resonator structure includes forming the repulsion region to surround the at least one wall.

19. The method of claim 11, wherein the repulsion region defines a water contact angle greater than 40.

20. The method of claim 11, wherein the repulsion region comprises a hydrophobic material.

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