A triangular dot glue crystal resonator

Abstract

The utility model discloses a triangular point glue crystal resonator relates to crystal resonator technical field, including ceramic base and quartz crystal piece, the ceramic base has been opened recess, be equipped with a plurality of lands in recess bottom, two conductive glue glue points with thickness are dotted on the land, the conductive glue glue point top is connected in quartz crystal piece, the middle position of two conductive glue glue points of quartz crystal piece is dotted with third conductive glue glue point, and three conductive glue glue points form triangular structure in vertical plane. The utility model wants to solve the technical problem in at providing a triangular point glue crystal resonator, and the defect of wafer peeling is overcome, and the stability between each component of quartz crystal resonator is improved to the ultrasonic product's vibration resistance through the change of quartz crystal wafer's point glue structure, strengthens.

Description

Technical Field

[0001] This utility model relates to the field of crystal resonator technology, specifically to a triangular dot-bonded crystal resonator. Background Technology

[0002] Quartz crystal oscillators are widely used in personal calculators, security systems, communications, radio applications, remote control units, and consumer electronics, spanning various industries. With technological advancements and changing demands, the reliability requirements for quartz crystals are becoming increasingly stringent. For example, vibration resistance requirements are rising, as seen in automotive devices and ultrasonic products. In current quartz crystal manufacturing processes, the four-point adhesive method cannot reliably ensure that ultrasonic products pass vibration resistance reliability tests. Customer feedback indicates a 0.3% defect rate for ultrasonic products produced using existing processes, with the defect being crystal detachment. To improve customer experience and enhance the reliability of ultrasonic products, further improvements are needed. Utility Model Content

[0003] Technical problem to be solved by the utility model

[0004] The technical problem to be solved by this utility model is to provide a triangular dispensing crystal resonator that overcomes the defect of crystal chip detachment. By changing the dispensing structure of the quartz crystal chip, the stability between the components of the quartz crystal resonator is improved, thereby enhancing the vibration resistance of ultrasonic products.

[0005] Technical solution

[0006] To solve the above problems, the technical solution provided by this utility model is as follows:

[0007] A triangular dot-bonded crystal resonator includes a ceramic substrate and a quartz crystal wafer. The ceramic substrate has a groove, and the bottom of the groove has several pads. Two conductive adhesive dots with a thickness are dotted on the pads. The conductive adhesive dots are connected to the quartz crystal wafer. A third conductive adhesive dot is dotted at the middle position of the two conductive adhesive dots on the quartz crystal wafer. The three conductive adhesive dots form a triangular structure in a vertical plane.

[0008] The ceramic substrate has grooves to provide space for the quartz crystal wafer and form a resonant cavity to protect the fragile quartz crystal wafer from physical damage and environmental influences. This is the basic structure constituting the complete package. Several pads are located at the bottom of the grooves as electrical connection points and mechanical fixing points. Conductive adhesive dots are attached above the quartz crystal wafer to establish a direct physical and electrical connection between the quartz crystal wafer and the conductive adhesive dots (and pads) below. A third conductive adhesive dot is located midway between the two conductive adhesive dots on the quartz crystal wafer, providing an additional mechanical support and fixing point in the central region of the wafer. This enhances mechanical stability, strengthens resistance to bending moments / torques, disperses stress, and prevents the "seesaw" effect. The three conductive adhesive dots form a triangular structure in the vertical plane, constructing a stable spatial support structure, enhancing geometric stability, optimizing uniform support, and improving vibration resistance.

[0009] Alternatively, the two conductive adhesive dots on a single pad may be the same size and thickness.

[0010] The core function of the technical feature that "the two conductive adhesive dots on a single pad are of the same size and thickness" is to ensure symmetry, consistency, and balance within the same pad area. Its specific effects are: electrical performance consistency: ensuring balanced resistance in the current path and stable signal; mechanical support symmetry: providing balanced support force, evenly distributing stress / strain, preventing single-point failure, and improving vibration resistance; thermal stress balance: ensuring symmetrical distribution of stress caused by thermal expansion, reducing the risk of thermal cycling failure; process stability and controllability: serving as a key process control point, reducing variation, ensuring quality, and improving yield. This feature directly serves the core objective of the utility model—enhancing vibration resistance and preventing wafer detachment. By ensuring balanced strength and symmetrical stress distribution at the connection points of each pad, it provides a stable and reliable foundation for the entire "triangular dot adhesive" structure (including the newly added third dot). If the two adhesive dots on the same pad have significantly different performance, even with the addition of a third dot, the pad area may still become a weak point, failing locally under vibration and ultimately leading to wafer detachment. Therefore, this symmetry requirement is a necessary prerequisite and important guarantee for improving the overall reliability of the connection structure.

[0011] Optionally, the center-to-center spacing of the two conductive adhesive dots on the pad is 1.5 to 3 times the thickness.

[0012] The center-to-center spacing of two conductive adhesive dots on a solder pad is limited to 1.5 to 3 times its thickness. Mechanically, this achieves stress dispersion within the single-dot solder pad area, providing balanced and stable support and maintaining the adhesive's own strength. Electrically, it ensures sufficient coverage of the solder pad, maintaining adequate adhesive thickness to guarantee low resistance and reliable electrical connections. In terms of process, it ensures the stability, repeatability, and high yield of the dispensing process, avoiding bridging and cold solder joints. In terms of reliability, it directly contributes to enhanced vibration and shock resistance, forming the foundation for the stability and reliability of the entire "triangular dispensing" structure (especially its core third dot). This spacing parameter is a key detail ensuring the high reliability of the connection point within a single solder pad area. If the spacing is too large or too small, even with an innovative triangular dispensing structure, the connection point in that solder pad area may become a weak point, failing first under vibration stress (such as dot cracking, detachment, or electrical open circuit), ultimately potentially leading to chip detachment.

[0013] Alternatively, all conductive adhesive dots may be the same size and thickness.

[0014] This further improves stress dispersion within the pad area, providing balanced and stable support and maintaining the strength of the colloid itself.

[0015] Optionally, the pads are provided in two places, and the conductive adhesive dots on the pads are respectively connected to the two electrodes of the quartz crystal sheet.

[0016] The quartz crystal is a piezoelectric element whose core function is to generate precise mechanical vibrations when an electric field is applied (and vice versa). To implement the oscillation circuit, the two electrodes of the quartz crystal must be led out and connected to an external driving circuit. The conductive adhesive not only conducts electricity but is also the main material used to bond and fix the quartz crystal to the grooves in the ceramic substrate. The two conductive adhesive dots on each pad (and the adhesive layer they form) together constitute the bonding interface between the electrode area and the substrate. The two pads (a total of four adhesive dots) provide the main anchor points for fixing the quartz crystal to the substrate.

[0017] Optionally, the edge of the electrode is shorter than the edge of the conductive adhesive dots on the outer edge.

[0018] To prevent electrode edge corrosion / silver migration, conductive silver paste contains silver ions. In the presence of electric fields, moisture, and contaminants, silver ions can migrate along electrode edges or the surface of the quartz crystal wafer. Silver dendrites may grow onto adjacent electrodes or grounded areas, causing electrical faults, and the migration process itself can damage the electrode structure. The conductive adhesive dots, shorter than the outer edge of the electrode, allow the conductive adhesive to completely cover the electrode edge, forming a physical barrier. This also enhances the stability and peel resistance of the mechanical connection. Stress is transferred and dispersed within the adhesive layer, rather than concentrated at the sharp geometric abrupt point of the electrode boundary. The encapsulation structure more effectively converts peeling forces (forces attempting to tear the wafer from the adhesive layer) into shear forces (forces parallel to the interface within the adhesive layer), and the adhesive generally has better shear resistance. The conductive adhesive layer acts like a "protective sleeve" covering the electrode edges, providing a physical barrier to prevent direct contact with external mechanical forces or chemical environments.

[0019] Optionally, the total thickness of the pads, the conductive adhesive dots, and the quartz crystal sheet is adapted to the depth of the groove.

[0020] Through precise dimensional matching, the wafer is securely clamped within the package. Its key functions are: Mechanical locking foundation: Providing fundamental constraints for the wafer against vibration and shock, preventing displacement and loosening, and serving as the basic physical guarantee for solving the "wafer detachment" problem; Connection optimizer: Optimizing the interface contact and stress state (slight compression) of the conductive adhesive, improving the electrical and mechanical reliability of the connection points; Sealing prerequisite: Ensuring the key geometric conditions for forming a reliable sealed cavity; Frequency stabilizer: Ensuring consistent wafer boundary conditions and maintaining frequency stability; "Triangular dispensing" function guarantee: Ensuring the effective load-bearing capacity of the third support point, enabling the triangular support structure to work collaboratively under vibration; Core of process control: These are critical dimensional parameters that require strict control during manufacturing, directly affecting product consistency and yield.

[0021] Alternatively, the ceramic base may be a one-piece molded structure.

[0022] More stable structure: No seams or connection points, resulting in higher overall strength; Good sealing: Suitable for applications requiring dustproof, waterproof, or airtightness; Reduced processing steps: One-piece molding reduces subsequent assembly and processing steps, improving production efficiency; High dimensional accuracy: One-piece molding makes it easier to ensure product dimensional consistency and accuracy.

[0023] Beneficial effects

[0024] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0025] The technical solution provided by this utility model adds a third conductive adhesive point located in the middle of the wafer, which together with the original two edge adhesive points forms a vertical triangular support. The geometric stability of the triangle is used to resist the torsional force under vibration and impact, thereby firmly fixing the wafer and preventing it from falling off. Attached Figure Description

[0026] Figure 1 A top view of a triangular dot-glued crystal resonator proposed as an embodiment of this utility model;

[0027] Figure 2 An assembly process diagram of a triangular dot-glued crystal resonator proposed for an embodiment of this utility model;

[0028] Figure 3 A cross-sectional view of a triangular dot-glued crystal resonator proposed as an embodiment of this utility model;

[0029] 1. Dispensing structure; 11. First dispensing dot; 12. Second dispensing dot; 13. Third dispensing dot; 14. Fourth dispensing dot; 15. Fifth dispensing dot; 16. Sixth dispensing dot; 17. First solder pad; 18. Second solder pad; 2. Ceramic base; 3. Quartz crystal wafer. Detailed Implementation

[0030] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0031] Example 1

[0032] Combined with appendix Figure 1-3 A triangular dispensing crystal resonator includes a ceramic substrate 2 and a quartz crystal wafer 3. The ceramic substrate 2 and the quartz crystal wafer 3 are electrically connected by dispensing structure 1. The ceramic substrate 2 is a one-piece molded structure. The ceramic substrate 2 has a groove, and the bottom of the groove has several pads. Two conductive adhesive dots with thickness are dotted on the pads, designated as the first adhesive dot 11 and the second adhesive dot 12. The conductive adhesive dots are connected to the quartz crystal wafer 3 above them. A third conductive adhesive dot is dotted at the midpoint between the two conductive adhesive dots on the quartz crystal wafer 3, designated as the fifth adhesive dot 15. The three conductive adhesive dots form a triangular structure in the vertical plane. A triangle is one of the most stable planar structures in mechanics. The three points are not on the same straight line, which together determine the position of the wafer in the horizontal direction and constrain its rotational degree of freedom about any axis (compared to two points which can only constrain one rotational degree of freedom). Theoretically, three-point support can provide a more uniform distribution of support force, allowing the wafer to be fixed more flatly on the substrate. The triangular structure can more effectively distribute vibrational energy to three support points and absorb energy through the elastic deformation of the colloid, greatly reducing the possibility of wafers falling off due to resonance or stress concentration. This is a key structural improvement for solving the defect rate of "wafer detachment".

[0033] By adding a third support point in the central region of the wafer, based on the existing two-point fixation, the adhesion area and bonding strength of the wafer on the substrate are greatly increased. When the device is subjected to vibration or impact, the wafer is prone to torsional or bending moments (like a seesaw). The third point, located at the center (or near the center), effectively resists these moments, preventing one end of the wafer from lifting or the entire wafer from twisting or deforming. The stress generated by vibration and impact is dispersed and absorbed by the three points, avoiding excessive stress concentration at the two original connection points, which could lead to adhesive cracking or failure. The original two-point, one-line structure is prone to rotational tendency around the connecting line under vibration (one end of the wafer lifts up, the other end presses down). The third point, located at the center, directly suppresses this rotational tendency.

[0034] The two conductive adhesive dots on a single pad are of the same size and thickness. All conductive adhesive dots are of the same size and thickness. When current flows from the quartz crystal electrode 3 through the two adhesive dots to the same pad, the resistance along the path is uniform. This avoids problems such as uneven current distribution or localized heating caused by resistance differences, ensuring the stability of the electrical connection and the consistency of signal quality. The expansion and contraction behavior of the two identical adhesive dots on the same pad during temperature changes, as well as the stress generated at their interface with the quartz crystal 3 and the pad, are synchronous and symmetrical. This helps reduce the risk of localized stress concentration and potential interface delamination caused by thermal cycling, especially in applications where ultrasonic products may experience temperature variations.

[0035] The center-to-center spacing between two conductive adhesive dots on a solder pad is 1.5 to 3 times the thickness. The distance between the center points of two conductive adhesive dots on a single solder pad (i.e., the spacing) is limited to 1.5 to 3 times the thickness of the adhesive dot. If the two dots are too close together (the spacing is much less than 1.5 times the thickness), their effective coverage area on the solder pad will highly overlap, essentially becoming a single, irregularly shaped large dot. The lower limit of 1.5 times the thickness ensures sufficient physical separation between the two dots, allowing them to function independently and distribute the load applied to the solder pad area. Covering a wider area of ​​the solder pad provides more balanced support and prevents excessive local stress. Maintaining a relatively "thick" shape for the adhesive dots (thickness not too small relative to the spacing) helps maintain their structural and adhesive strength. Ensuring reliable electrical connection and sufficient contact area (upper limit: 3 times the thickness), the two dots, after spreading, can effectively cover most of the critical area of ​​the solder pad, ensuring continuity of electrical connection and low contact resistance. The adhesive dots maintain the necessary thickness after lamination, ensuring good conductivity and sufficient mechanical strength. Maintaining a relatively "concentrated" state for the adhesive dots facilitates process control and ensures the quality of each dot. Before dispensing and curing, the adhesive dots are hemispherical or dome-shaped with a certain height (thickness). After curing, ideally, the adhesive dots spread into regularly shaped, clearly defined, approximately cylindrical or flattened spherical caps with uniform thickness. A spacing range of 1.5 to 3 times the initial dispensing volume, combined with controlled dispensing amount, helps to create the following after curing: Independent dot outlines: Two dots can be clearly distinguished, neither merging nor too far apart. Appropriate spreading diameter: The diameter of the adhesive dots will be slightly larger than the initial dispensing diameter, but controlled within the pad size. Maintaining the target thickness: Avoiding excessively thin adhesive layers due to over-spreading.

[0036] Two pads are provided, with conductive adhesive dots on the pads connecting to the two electrodes of the quartz crystal wafer 3. The other pad has conductive adhesive dots 13 and 14. The two pads are symmetrically arranged within the groove, of the same size, to uniformly distribute stress. The third conductive adhesive dot here is the sixth dot 16. The original two pads (four dots) form a support "line," while the newly added third point forms a triangular support structure in the middle. This geometric relationship is the core of improving vibration resistance. Functional division: The two pads and their adhesive dots mainly undertake electrical connections and direct fixation of the electrode areas. The newly added third point does not undertake electrical functions (it connects to the metallization layer of the non-electrode area of ​​the wafer or the wafer itself, and does not participate in the signal circuit), purely providing additional mechanical support to resist torsional torque caused by vibration. Synergistic enhancement: A stable pad base (two / four dots) is a prerequisite for increasing the effectiveness of the third point. Only when the connection of the pad area is sufficiently reliable can the third point fully exert its "torsion resistance" function; otherwise, the pad area itself may fail first. Conversely, the third point stabilizes the chip center and reduces the torsional stress on the adhesive dots in the pad area.

[0037] The edge of the electrode is shorter than the edge of the conductive adhesive dots at the outer edge. There is a metallized electrode (usually a circular or square area) at the bottom of the quartz crystal wafer 3. This electrode area is covered with a layer of conductive adhesive spread after application (for a single pad area, two initial adhesive dots may fuse or closely adhere to each other after spreading, forming a continuous adhesive layer). The area covered by the conductive adhesive layer (its outer boundary) is larger than the electrode area below (its boundary). In other words, the conductive adhesive acts like a "protective shield," completely covering and enveloping the edge of the electrode; all boundaries of the electrode are within the conductive adhesive coverage area and are not exposed outside the adhesive layer. The conductive silver paste contains silver ions. In the presence of an electric field, moisture, and contaminants, silver ions may migrate along the electrode edge or the surface of the quartz crystal wafer 3. Completely covering the electrode edge with conductive adhesive forms a physical barrier. This isolates the environment, preventing moisture and contaminants from directly contacting the vulnerable electrode edge. It also blocks the migration path, as silver ion migration requires a surface path. Covering the electrode edges effectively cuts off the direct pathway for ions to migrate along the electrode boundary to the non-electrode region of the quartz crystal sheet 3 or other electrodes, forcing any possible migration to occur only inside the conductive adhesive or at the adhesive-quartz interface, thus greatly reducing the risk.

[0038] Vibration and shock are most likely to induce and propagate cracks at geometric discontinuities, such as electrode edges. The encapsulation structure eliminates this critical stress concentration point, transforming destructive peeling forces into shear forces that the adhesive layer can withstand more effectively. The conductive adhesive encapsulates the electrode edges, similar to the anchoring of reinforcing bars in reinforced concrete; the encapsulation structure physically "locks" the electrode edges, significantly improving the connection point's resistance to peeling failure caused by vibration, shock, and thermal stress.

[0039] The total thickness of the pads, conductive adhesive dots, and quartz crystal 3 is adapted to the depth of the groove. The total thickness is calculated as: (Thickness of the pads at the bottom of the groove in the ceramic base 2) + (Thickness of the cured conductive adhesive dots) + (Thickness of the quartz crystal 3 itself). This total thickness needs to be precisely matched to the depth of the groove in the ceramic base 2 (“fitting”). The core meaning of “fitting” is: Target state: After the quartz crystal 3 is fixed to the pads at the bottom of the groove with conductive adhesive, its upper surface should be in a specific relative position to the opening plane of the groove in the ceramic base 2 (i.e., the upper surface of the base). Key requirement: This usually means that the total thickness is slightly greater than the groove depth, forming a slight “interference fit” or “pre-tightening” state. However, it may also be equal to or have a very small negative tolerance (which needs to be judged in conjunction with other sealing structures). The core is controllability and stability. To achieve the function of the “triangular dot” structure, the newly added third central adhesive dot needs to participate in load-bearing and provide support. Compacted State (Total Thickness >= Groove Depth): Activate the third point: Ensure the center adhesive dot is also compacted, forming effective contact with the wafer and the underlying substrate (possibly through a special design, such as a boss within the groove or direct application of adhesive to the bottom of the substrate), truly participating in the support structure. If the wafer is loose, the center point may have poor contact or be unloaded. Ensure the triangular support is under load: Only when the wafer is compacted can the force generated during vibration be effectively transmitted and dispersed through all three adhesive dots. If loose, vibration energy may cause the wafer to repeatedly impact the adhesive dots or substrate, accelerating failure.

[0040] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A triangular dot-coated crystal resonator, characterized in that, The device includes a ceramic base and a quartz crystal sheet. The ceramic base has a groove, and the bottom of the groove has several pads. Two conductive adhesive dots with a thickness are placed on the pads. The conductive adhesive dots are connected to the quartz crystal sheet. A third conductive adhesive dot is placed between the two conductive adhesive dots on the quartz crystal sheet. The three conductive adhesive dots form a triangular structure in the vertical plane.

2. The triangular dot-bonded crystal resonator according to claim 1, characterized in that, The two conductive adhesive dots on a single pad are the same size and thickness.

3. A triangular dot-bonded crystal resonator according to claim 2, characterized in that, The center-to-center distance between the two conductive adhesive dots on the pad is 1.5 to 3 times the thickness.

4. A triangular dot-bonded crystal resonator according to claim 2, characterized in that, All conductive adhesive dots are the same size and thickness.

5. A triangular dot-bonded crystal resonator according to claim 1, characterized in that, The pads are provided in two places, and the conductive adhesive dots on the pads are respectively connected to the two electrodes of the quartz crystal sheet.

6. A triangular dot-bonded crystal resonator according to claim 5, characterized in that, The edge of the electrode is shorter than the edge of the conductive adhesive dots on the outer edge.

7. A triangular dot-bonded crystal resonator according to claim 1, characterized in that, The total thickness of the pads, the conductive adhesive dots, and the quartz crystal sheet is adapted to the depth of the groove.

8. A triangular dot-bonded crystal resonator according to any one of claims 1 to 7, characterized in that, The ceramic base is a one-piece molded structure.

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