Method and system for blocking splash
By constructing the SiO2 passivation layer on the surface of the surface acoustic wave filter, the hidden dangers of splashes to the device during the packaging process are solved, and the reliability and packaging effect of the device are improved.
Patent Information
- Application Number
- CN202510187879.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2025-07-18
AI Technical Summary
The prior art is difficult to effectively block splashes generated during the packaging of surface acoustic wave filters, resulting in a reduction in device reliability.
The passivation layer, especially the SiO2 passivation layer, is constructed on the surface of the surface acoustic wave device, by adjusting the thickness and designing the structure to optimize device performance, and the passivation layer is placed on the surface of the device to block splashes.
It improves the reliability of the device, protects the device from splashes, reduces the difficulty of sealing the tube, and increases the overall reliability of the device.
Smart Images
Figure CN120342351A_ABST
Abstract
Description
Background Art
[0002] Energy storage welding sealing is a special military process and plays an irreplaceable role in the packaging of surface acoustic wave (SAW) filters. The outer shell used in energy storage welding is a nickel-plated metal cap and a gold-plated base. The nickel-plated cap is aligned and fitted with the base through the gold-plated base welding ring, and under the condition of large current discharge, the metal of the cap and the metal of the base are melted and sealed. In an ideal fitting situation, the side wall of the cap does not contact the step of the base, but there is a certain distance left. When a point or line on the side wall of the cap contacts the step of the base, the instantaneous contact resistance is too large, and a large amount of heat will be generated when the sealing tube current passes, causing the contact point to melt and generate spatter.
[0003] Common methods for controlling spatter: selection of welding materials, selection of electrode materials, selection of electrode positive and negative poles, setting of the structure size of the sealing rib, control of welding energy, control of electrode pressure, current preheating, pretreatment before electroplating, types and control of electroplating coatings, etc., need to be comprehensively required and controlled. After control, there is still a possibility of spatter generation. Even though PIND can screen out the movable redundant substances generated by spatter, some spatter metal particles will form immovable molten redundant substances after cooling, and this type of redundant substance cannot be screened out by PIND. Summary of the Invention
[0004] The present application provides a method and system for blocking spatter to eliminate the potential hazards caused by spatter to devices.
[0005] In a first aspect, a method for blocking spatter is provided, including the following steps:
[0006] Construct a passivation layer;
[0007] Set the passivation layer on the surface of the SAW device;
[0008] Use the passivation layer to block spatter.
[0009] In the above technical solution, by constructing a passivation layer; setting the passivation layer on the surface of the SAW device; using the passivation layer to block spatter; the reliability of the device is increased, and the device is protected from the influence of spatter.
[0010] In a specific feasible implementation scheme, the step of constructing the passivation layer specifically includes:
[0011] Through the research on the thickness of the passivation layer and the design structure of the SAW device, influencing characteristics are obtained;
[0012] Use the influencing characteristics to optimize the structure of the SAW device;
[0013] Construct the passivation layer based on the optimized structure of the SAW device.
[0014] In a specific feasible implementation, the designed structure of the SAW device includes: a mirror structure, a conventional structure, a fan structure, a longitudinal coupling structure, a transverse coupling structure, and an impedance element structure.
[0015] In a specific feasible implementation, the influencing characteristics include: SAW devices with mirror structure, conventional structure, and fan structure are not sensitive to the thickness of the passivation layer; within a thickness range of 3% of the relative film thickness, the increase in the thickness of the passivation layer only affects the frequency of the SAW device.
[0016] In a specific feasible implementation, the step of setting the passivation layer on the surface of the SAW device is specifically:
[0017] Spray the passivation layer on the surface of the SAW device; or electroplate the passivation layer on the surface of the SAW device.
[0018] In a specific feasible implementation, the thickness of the passivation layer wraps the interdigital electrodes of the SAW device.
[0019] In a specific feasible implementation, the thickness of the passivation layer is greater than the thickness of the interdigital electrodes of the SAW device.
[0020] In a specific feasible implementation, the step of using the passivation layer to block spatter is specifically:
[0021] Design the SAW device so that the center frequency after setting the passivation layer meets the target frequency, and use the passivation layer to block spatter.
[0022] In a specific feasible implementation, the passivation layer includes a SiO2 passivation layer.
[0023] In a second aspect, a system for blocking spatter is provided, including:
[0024] A construction module for constructing a passivation layer;
[0025] A setting module for setting the passivation layer on the surface of the SAW device;
[0026] A test module for using the passivation layer to block spatter.
[0027] In the above technical solution, by constructing a passivation layer; setting the passivation layer on the surface of the SAW device; using the passivation layer to block spatter; the reliability of the device is increased, and the device is protected from the influence of spatter. Description of the Drawings
[0028] Figure 1 It is a flowchart of the method for blocking splashes provided by the embodiment of the present application;
[0029] Figure 2 It is a structural block diagram of the system for blocking splashes provided by the embodiment of the present application;
[0030] Figure 3 It is a schematic diagram of the influence of different passivation layer thicknesses on the device performance provided by the embodiment of the present application;
[0031] Figure 4 It is a schematic diagram of the performance of the SAW device with optimized structure provided by the embodiment of the present application;
[0032] Figure 5 It is a structural schematic diagram of the redundant splashes provided by the embodiment of the present application;
[0033] Figure 6 It is a structural schematic diagram before and after the passivation layer is provided in the embodiment of the present application. Detailed implementation manners
[0034] The present application will be further described in detail below with reference to the drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more distinct.
[0035] The special term "exemplary" here means "serving as an example, an embodiment or an illustration". Any embodiment described as "exemplary" here does not have to be interpreted as superior or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.
[0036] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.
[0037] To facilitate the understanding of the method and system for blocking splashes provided by the embodiments of the present application, the application scenario will be described first. The method and system for blocking splashes provided by the embodiments of the present application are used to eliminate the potential hazards caused by splashes to devices. Energy storage welding sealing is a special military process and plays an irreplaceable role in the packaging of surface acoustic wave (SAW) filters. The outer shell used in energy storage welding is a nickel-plated metal cap and a gold-plated base. The nickel-plated cap is aligned and fitted with the base through the gold-plated base welding ring, and the metal of the cap and the metal of the base are melted and sealed under the condition of large current discharge. In an ideal fitting situation, there is a certain distance between the side wall of the cap and the step of the base instead of contact. When a point or line on the side wall of the cap contacts the step of the base, the instantaneous contact resistance is too large, and a large amount of heat will be generated when the sealing tube current passes, causing the contact point to melt and generate splashes. Common methods for controlling splashes include: selection of welding materials, selection of electrode materials, selection of electrode positive and negative poles, setting of the structural dimensions of the sealing ribs, control of welding energy, control of electrode pressure, current preheating, pre-treatment before electroplating, types and control of electroplating coatings, etc., and comprehensive requirements and controls are required. After control, there is still a possibility of splashes. Even though the movable redundant objects generated by splashes can be screened out through PIND, some splashed metal particles will form immovable molten redundant objects after cooling, and such redundant objects cannot be screened out in PIND. For this reason, the embodiments of the present application provide a method and system for blocking splashes to eliminate the potential hazards caused by splashes to devices. The following will be described in detail with specific drawings by way of embodiments.
[0038] Reference Figures 1 to 6 , Figure 1 is a flowchart of the method for blocking splashes provided by the embodiments of the present application; Figure 2 is a structural block diagram of the system for blocking splashes provided by the embodiments of the present application; Figure 3 is a schematic diagram of the influence of different passivation layer thicknesses on the performance of the device provided by the embodiments of the present application; Figure 4 is a schematic diagram of the performance of the SAW device with optimized structure provided by the embodiments of the present application; Figure 5 is a structural schematic diagram of the splash redundant objects provided by the embodiments of the present application; Figure 6 is a structural schematic diagram before and after the passivation layer is provided by the embodiments of the present application.
[0039] In Figure 1 , the embodiments of the present application provide a method for blocking splashes, including the following steps:
[0040] Construct a passivation layer;
[0041] Set the passivation layer on the surface of the SAW device;
[0042] Use the passivation layer to block splashes.
[0043] In the above technical solution, a passivation layer is constructed; the passivation layer is disposed on the surface of the SAW device; the passivation layer is used to block splashes; the reliability of the device is increased, and the device is protected from splashes.
[0044] In a specific feasible embodiment, the step of constructing the passivation layer specifically includes:
[0045] By studying the thickness of the passivation layer and the design structure of the SAW device, influencing characteristics are obtained;
[0046] Using the influencing characteristics to optimize the structure of the SAW device;
[0047] Based on the optimized structure of the SAW device, the passivation layer is constructed.
[0048] In a specific feasible embodiment, the design structure of the SAW device includes: a mirror structure, a conventional structure, a fan-shaped structure, a longitudinal coupling structure, a transverse coupling structure, and an impedance element structure.
[0049] In a specific feasible embodiment, the influencing characteristics include: SAW devices with mirror structures, conventional structures, and fan-shaped structures are insensitive to the thickness of the passivation layer; within a thickness range of 3% of the relative film thickness, an increase in the thickness of the passivation layer only affects the frequency of the SAW device.
[0050] In a specific feasible embodiment, the step of disposing the passivation layer on the surface of the SAW device is specifically:
[0051] The passivation layer is sprayed on the surface of the SAW device; or, the passivation layer is electroplated on the surface of the SAW device.
[0052] In a specific feasible embodiment, the thickness of the passivation layer wraps the interdigital electrodes of the SAW device.
[0053] In a specific feasible embodiment, the thickness of the passivation layer is greater than the thickness of the interdigital electrodes of the SAW device.
[0054] In a specific feasible embodiment, the step of using the passivation layer to block splashes is specifically:
[0055] Design the SAW device so that its center frequency after setting the passivation layer meets the target frequency, and use the passivation layer to block splashes.
[0056] In a specific feasible embodiment, the passivation layer includes a SiO2 passivation layer. The SiO2 thin film has the characteristics of good absorbability, good wear resistance, strong erosion resistance, and good insulation. As the passivation layer of the chip, it is required to have water solubility and insulation. At the same time, the passivation layer also needs to have high density and good uniformity to ensure the consistency of frequency. In addition, it is also required that it is not easy to fall off and crack during the process preparation, and does not add factors that affect the electrical performance of the device, etc.
[0057] Specifically, by studying the influence of passivation layers with different thicknesses on the electrical performance of SAW filters with 6 different design structures, namely, the mirror structure, the conventional structure, the fan structure, the longitudinal coupling structure, the transverse coupling structure, and the impedance element structure, it is found that the SAW filters with the mirror structure, the conventional structure, and the fan structure are not very sensitive to the thickness of the passivation layer. Within the thickness range of the passivation layer with a relative film thickness of about 3%, the increase of the passivation layer only affects the frequency of the SAW filter. Through this characteristic, the structure of the SAW device is optimized. Design a SAW device with a relatively high center frequency, so that after passivating a certain thickness of SiO2, the center frequency meets the target frequency. Seal the tube of this device and conduct screening tests. The tests prove that the passivation layer plays a role in blocking spatter.
[0058] In this application, by preparing a passivation layer for the SAW device, it plays a protective role for the device, so that the excess substances generated by spatter will not affect the performance of the device. After control, there is still a possibility of spatter during the energy storage welding seal, and metal spatter may cause the device to fail. To increase the reliability of the device, it is therefore necessary to add a layer of SiO2 thin film on the surface of the device to protect the device from spatter. If the passivation layer wants to effectively protect the device, the thickness of the passivation layer needs to be greater than the thickness of the interdigital electrodes, that is, the passivation layer wraps the interdigital electrodes.
[0059] In the above technical solution, adding a layer of SiO2 thin film on the surface of the device can not only be used to protect the device from spatter, but also avoid being affected by other excess substances. It can reduce the difficulty of sealing the tube and increase the reliability of the device.
[0060] Furthermore, referring to Figure 3 , it can be seen that within the range of (relative film thickness of about 3.6%), the passivation layer mainly plays the role of mass loading, reducing the frequency of the SAW filter and having no effect on other performance indicators.
[0061] Referring to Figure 4 , by designing a SAW device with a relatively high center frequency, after passivating it with SiO2, the center frequency meets the target frequency. Seal the tube of this device with the tube sealing parameters that are prone to spatter.
[0062] Referring toFigure 5 and Figure 6 After the screening test, the electrical properties of the SAW filter did not change. The device was decapped, and the surface of the chip was observed under a high-power microscope. No cracking was found in the surface SiO2 film. Spatter occurred in the functional areas of some devices, indicating that the passivation layer played a role in blocking the spatter.
[0063] In Figure 2 the embodiments of the present application provide a system for blocking spatter, including:
[0064] A construction module for constructing a passivation layer;
[0065] A setting module for setting the passivation layer on the surface of the SAW device;
[0066] A test module for using the passivation layer to block spatter.
[0067] In the above technical solution, by constructing a passivation layer; setting the passivation layer on the surface of the SAW device; using the passivation layer to block spatter; the reliability of the device is increased, and the device is protected from the influence of spatter.
[0068] Those skilled in the art of the present application know that the present application can be implemented as a system, a method, or a computer program product.
[0069] Therefore, the present disclosure can be specifically implemented in the following forms, that is: it can be completely hardware, can also be completely software (including firmware, resident software, microcode, etc.), and can also be a combination of hardware and software, generally referred to as "circuit", "module" or "system" in this article. In addition, in some embodiments, the present application can also be implemented in the form of a computer program product in one or more computer-readable media, which contains computer-readable program code.
[0070] Any combination of one or more computer-readable media may be employed. The computer-readable media may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example - but not limited to - an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the present document, a computer-readable storage medium may be any tangible medium that contains or stores a program which can be used by or in connection with an instruction execution system, apparatus, or device.
[0071] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application. On this basis, various substitutions and improvements can be made to the present application, and all of these fall within the protection scope of the present application.
Claims
1. A method for blocking splashes, characterized in that, It includes the following steps: Construct a passivation layer; Set the passivation layer on the surface of the SAW device; Use the passivation layer to block splashes.
2. The method for blocking splashes according to claim 1, characterized in that, The step of constructing the passivation layer specifically includes: Obtain influencing characteristics through research on the thickness of the passivation layer and the design structure of the SAW device; Use the influencing characteristics to optimize the structure of the SAW device; Based on the optimized structure of the SAW device, construct the passivation layer.
3. The method for blocking splashes according to claim 2, wherein The design structure of the SAW device includes: mirror structure, conventional structure, fan structure, longitudinal coupling structure, transverse coupling structure, and impedance element structure.
4. The method for blocking splashes according to claim 3, characterized in that, The influencing characteristics include: SAW devices with mirror structure, conventional structure, and fan structure are insensitive to the thickness of the passivation layer; within the thickness range of 3% of the relative film thickness, the increase in the thickness of the passivation layer only affects the frequency of the SAW device.
5. The method for blocking splashes according to claim 4, wherein The step of setting the passivation layer on the surface of the SAW device is specifically: Spray the passivation layer on the surface of the SAW device; or electroplate the passivation layer on the surface of the SAW device.
6. The method for blocking splashes according to claim 5, wherein, The thickness of the passivation layer wraps the interdigital electrodes of the SAW device.
7. The method for blocking splashes according to claim 6, characterized in that, The thickness of the passivation layer is greater than the thickness of the interdigital electrodes of the SAW device.
8. The method for blocking splashes according to claim 7, wherein, The step of using the passivation layer to block splashes is specifically: Design the SAW device so that its center frequency after setting the passivation layer conforms to the target frequency, and use the passivation layer to block splashes.
9. The method for blocking splashes according to claim 8, wherein, The passivation layer includes a SiO2 passivation layer.
10. A system for blocking splashes, characterized in that, It includes: A construction module for constructing a passivation layer; A setting module for setting the passivation layer on the surface of the SAW device; A test module for using the passivation layer to block splashes.