Packaging structure and method of embedded filter

Abstract

The invention provides a packaging structure of an embedded filter, and the structure comprises a glass-based substrate which is provided with a blind groove; the blind groove is filled with the first conductive layer; the length, width and height of the first conductive layer are smaller than or equal to the length, width and height of the blind groove. Through the design of the blind groove, the first organic protection layer can be completely embedded into the blind groove, the interface fitting structure of the first organic protection layer and the glass substrate is changed, the reliability of the radio frequency filter is effectively improved, and meanwhile the packaging thickness of the whole radio frequency filter can be reduced.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular, to a packaging structure and method for an embedded filter. Background Art

[0002] Glass-based passive devices are a type of electronic component manufactured with glass as the substrate material, including but not limited to resistors, capacitors, inductors, etc. Glass substrates have advantages such as high transparency, good insulation, chemical stability, and low thermal expansion coefficient. For example, in some high-precision electronic devices, the low thermal expansion coefficient of the glass substrate can ensure that the performance of the device remains stable when the temperature changes, which is crucial for maintaining the normal operation of the circuit.

[0003] These passive devices are widely used in modern electronic technologies, such as for signal filtering, coupling, and matching in communication devices; for signal conversion and transmission in sensors, etc.

[0004] To ensure that PI can function stably on the glass surface for a long time, good adhesion is required between the two. The magnitude of the adhesion directly affects the reliability and service life of the device. If the adhesion is insufficient, delamination is likely to occur, resulting in a decline or even failure of the device performance. This requires that during the manufacturing process, appropriate surface treatment and coating processes be used to enhance the bonding force between PI and glass.

[0005] The interface between PI and the glass surface needs to remain stable under different conditions such as temperature, humidity, and mechanical stress. Due to the different thermal expansion coefficients of glass and PI, thermal stress may be generated at the interface when the temperature changes. At the same time, in a high-humidity environment, water molecules may penetrate into the interface, affecting the bonding between the two. Therefore, measures need to be taken to improve the stress resistance and moisture-proof ability of the interface to maintain the stability of the interface. Summary of the Invention

[0006] To achieve the above object, in the first aspect of this application, a packaging structure for an embedded filter is proposed, including:

[0007] A glass-based substrate with a blind groove formed thereon;

[0008] A first conductive layer filled inside the blind groove; the length, width, and height of the first conductive layer are respectively less than or equal to the length, width, and height of the blind groove.

[0009] By opening blind vias on a glass substrate, filling the interior of the blind vias with a first conductive layer, and defining the size of the first conductive layer to be less than or equal to the size of the blind vias, the basic framework of the embedded filter package structure is constructed. The glass substrate provides a stable bearing foundation, the blind vias provide a specific space for the subsequent arrangement of components such as conductive layers, and the first conductive layer can serve as an important part of subsequent circuit structures and participate in functions such as conduction and signal transmission of the filter. This structural design is conducive to the orderly integration and layout of each functional component of the filter, laying a foundation for the packaging and performance of the filter.

[0010] Specifically, the size of the blind vias ≥ 0.5mm * 0.5mm * 5um.

[0011] Through the above technical means, to a certain extent, the stability and manufacturability of the overall structure of the embedded filter are guaranteed, which helps the filter to achieve corresponding filtering and other functions according to the expected design.

[0012] Specifically, it further includes: a first protective layer; the first protective layer covers the first conductive layer.

[0013] By adding the first protective layer and covering the first conductive layer, it can protect the first conductive layer. It can prevent the first conductive layer from being eroded by external environmental factors (such as moisture, dust, corrosive substances, etc.), and avoid problems such as a decrease in conductivity and short circuit due to long-term exposure. Thereby, the reliability and durability of the embedded filter in different usage environments are improved, ensuring the long-term stable operation of the filter and maintaining the consistency of its performance.

[0014] Specifically, the thickness of the first protective layer is the same as the height of the blind vias.

[0015] Through the above technical solution, when the protective layer covers the first conductive layer, it can completely and fittingly fill the remaining space in the blind vias, which not only ensures the full protection of the first conductive layer but also makes the entire package structure more regular and compact in the thickness direction, avoiding problems such as uneven structure and affecting subsequent processes caused by unreasonable thickness of the protective layer, and facilitating the overall performance optimization of the entire embedded filter package structure and subsequent possible assembly operations.

[0016] Specifically, there are at least three conductive layers and protective layers on the glass substrate.

[0017] Specifically, the maximum normal stress at the contact part between the first protective layer and the blind vias is less than or equal to 77.906 Mpa.

[0018] In the second aspect of the present application, a packaging method for an embedded filter is provided, including the following steps:

[0019] S1. Provide a glass substrate with blind vias formed thereon.

[0020] S2. Form the routing profile of the metal conductor of the first conductive layer within the blind vias.

[0021] S3. Cover the first conductive layer with a first protective layer, where the thickness of the first protective layer is the same as the height of the blind vias.

[0022] S4. Etch the dielectric layer and the upper electrode metal conductor on the basis of the first conductive layer, and sequentially form the remaining conductive layers and protective layers.

[0023] S1 specifically includes:

[0024] S101. Provide a glass substrate and cover the mask area of the blind vias with a photolithography mask.

[0025] S102. Use dry etching to etch out on the glass substrate with dimensions not less than 0.5mm * 0.5mm * 5um.

[0026] S2 specifically includes:

[0027] S201. Cover the mask area of the first conductive layer within the blind vias with a photolithography mask.

[0028] S202. Use the photolithography process to etch the area within the blind vias that is not the mask area of the first conductive layer.

[0029] S4 specifically includes:

[0030] S401. Use PVD, PECVD, and etching technologies to complete the dielectric layer and the upper electrode metal conductor on the basis of the first conductive layer.

[0031] S402. Sequentially form the remaining conductive layers and protective layers on the basis of the dielectric layer and the upper electrode metal conductor, and interconnect the conductive layers. Description of the Drawings

[0032] The drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The drawings illustrate the embodiments and, together with the description, are used to explain the principles of the present application. Other embodiments and many of the expected advantages of the embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily drawn to scale with each other. The same reference numerals refer to corresponding like parts.

[0033] Figure 1 is a schematic structural diagram of a packaging structure of an embedded filter according to an embodiment of the present application;

[0034] Figure 2It is a simulation comparison diagram of a packaging structure of an embedded filter according to a specific embodiment of the present application;

[0035] Figure 3 It is a simulation comparison diagram of a Baseline structure filter;

[0036] Figure 4 It is a flowchart of a packaging method of an embedded filter according to an embodiment of the present application. Detailed implementation manners

[0037] In the following detailed description, reference is made to the accompanying drawings, which form a part of the detailed description and illustrate illustrative specific embodiments in which the present application can be practiced. In this regard, directional terms such as "top", "bottom", "left", "right", "upper", "lower", etc. are used with reference to the orientation of the described figures. Since the components of the embodiments can be positioned in several different orientations, the directional terms are used for the purpose of illustration and are in no way limiting. It should be understood that other embodiments can be utilized or logical changes can be made without departing from the scope of the present application. Therefore, the following detailed description should not be taken in a limiting sense, and the scope of the present application is defined by the appended claims.

[0038] Figure 1 It is a schematic structural diagram of a packaging structure of an embedded filter according to an embodiment of the present application. As Figure 1 shown, a packaging structure of an embedded filter includes:

[0039] A glass-based substrate, on which a blind groove is formed;

[0040] A first conductive layer, which is filled inside the blind groove; the length, width and height of the first conductive layer are respectively less than or equal to the length, width and height of the blind groove, and the first conductive layer is filled inside the blind groove, and the size of the first conductive layer is limited to be less than or equal to the size of the blind groove, thus constructing the basic framework of the embedded filter packaging structure. The glass-based substrate provides a stable bearing foundation, the blind groove provides a specific space for the subsequent arrangement of components such as conductive layers, and the first conductive layer can serve as an important part of subsequent circuit structures and participate in the realization of functions such as conduction and signal transmission of the filter. This structural design is conducive to the orderly integration and layout of each functional component of the filter and lays a foundation for the packaging and performance of the filter.

[0041] Specifically, the size of the blind groove is ≥ 0.5 mm * 0.5 mm * 5 μm, which stipulates the minimum size requirement of the blind groove. Sufficient size can ensure that the subsequent filled first conductive layer and other possible functional layers (such as protective layers, etc.) have appropriate space, avoiding problems such as mutual interference between layers and difficult process implementation due to too small space. At the same time, it also guarantees the stability and manufacturability of the overall structure of the embedded filter to a certain extent, and helps the filter to achieve corresponding filtering and other functions according to the expected design.

[0042] Specifically, it also includes: a first protective layer; the first protective layer covers the first conductive layer and can play a protective role for the first conductive layer. It can prevent the first conductive layer from being eroded by external environmental factors (such as moisture, dust, corrosive substances, etc.), and avoid problems such as a decrease in conductivity and short circuit due to long-term exposure. Thereby, it improves the reliability and durability of the embedded filter in different use environments, ensures the long-term stable operation of the filter, and maintains the consistency of its performance.

[0043] Specifically, the thickness of the first protective layer is the same as the height of the blind groove, so that when the protective layer covers the first conductive layer, it can completely and fittingly fill the remaining space in the blind groove, which not only ensures the full protection of the first conductive layer, but also makes the entire packaging structure more regular and compact in the thickness direction, avoiding problems such as uneven structure and affecting subsequent processes caused by unreasonable thickness of the protective layer, and is conducive to the overall performance optimization of the entire embedded filter packaging structure and subsequent possible assembly and other operations.

[0044] In a specific embodiment, as Figure 2 shown, by designing a blind groove structure (not less than 0.5 mm * 0.5 mm * 5 μm) on the glass substrate, the interface structure between the PI material and the glass substrate is changed, effectively restricting the deformation of the PI material, so that the stress generated by the temperature change of the PI material in the reliability test is reduced.

[0045] Compared with Figure 3 it can be found that the simulation data shows that the maximum normal stress received by P1 of the Baseline structure (original scheme) is 149.61 Mpa, and the maximum normal stress received by P1 of the P1 embedded structure (patent scheme) is 77.906 Mpa, with a decrease of about 48%, indicating that the glass-based blind groove design is effective in improving the reliability of the PI material.

[0046] As Figure 4 shown, a packaging method for an embedded filter includes the following steps:

[0047] S1. Provide a glass substrate with a blind groove opened on it;

[0048] S2. Form the running line shape of the metal conductor of the first conductive layer in the blind groove;

[0049] S3. Cover a first protective layer on the first conductive layer, and the thickness of the first protective layer is the same as the height of the blind groove;

[0050] S4. Etch the dielectric layer and the upper plate metal conductor on the basis of the first conductive layer, and sequentially form the remaining conductive layer and the protective layer.

[0051] S1 specifically includes:

[0052] S101. Provide a glass substrate, and cover the photolithography mask on the blind groove mask area;

[0053] S102. Use dry etching to etch out a size not less than 0.5mm * 0.5mm * 5um on the glass substrate.

[0054] S2 specifically includes:

[0055] S201. Cover the photolithography mask on the first conductive layer mask area in the blind groove;

[0056] S202. Use the photolithography process to etch the non-first conductive layer mask area in the blind groove.

[0057] S4 specifically includes:

[0058] S401. Use PVD, PECVD and etching technologies to complete the dielectric layer and the upper plate metal conductor on the basis of the first conductive layer;

[0059] S402. Sequentially form the remaining conductive layer and the protective layer on the basis of the dielectric layer and the upper plate metal conductor, and interconnect the conductive layers.

[0060] In a specific embodiment, the filter structure has a stacked design of at least three layers of organic protective layers and metal conductors on a glass substrate. First, a blind via structure is etched on the glass substrate using photolithography masks and dry etching techniques. The size of the blind via is not less than 0.5mm * 0.5mm * 5um. Film lithography is performed inside the blind via to complete the linear shape of the first layer of metal conductor. The thickness of the first layer of organic protective layer is the same as the thickness of the blind via, and electroplating of the first layer of metal conductor is completed at the opening position of the first layer of organic protective layer. Based on the first layer of metal conductor, the structural morphology of the dielectric layer and the upper electrode metal conductor of the filter capacitor structure is completed using PVD, PECVD, and etching techniques. Subsequently, the stacked design of the second / third layer of metal conductor traces and organic protective layers is completed in sequence to achieve the trace interconnection of the metal conductors in the three-layer stacked structure, complete the design of the metal conductors of the entire RF filter, and design a pad structure on the last layer of traces. A metal conductive post and a solder ball structure are designed on the pad structure to interconnect the metal conductor traces of the entire RF filter with the metal conductive post and the solder ball structure. Through the design of the blind via in this application, the first layer of organic protective layer can be completely embedded in the blind via, changing the interface bonding structure between the first layer of organic protective layer and the glass substrate, effectively improving the reliability of the RF filter and also reducing the package thickness of the entire RF filter.

[0061] Obviously, those skilled in the art can make various modifications and changes to the embodiments of the present application without departing from the spirit and scope of the present application. In this way, if these modifications and changes are within the scope of the claims of the present application and their equivalent forms, the present application also aims to cover these modifications and changes. The word "comprising" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A packaging structure of an embedded filter, characterized in that: include: A glass-based substrate, wherein a blind groove is formed on the glass-based substrate; a first conductive layer, wherein the first conductive layer is filled inside the blind groove; The length, width and height of the first conductive layer are respectively less than or equal to the length, width and height of the blind groove.

2. The packaging structure of an embedded filter according to claim 1, characterized in that: The size of the blind groove is ≥0.5mm*0.5mm*5um.

3. The packaging structure of an embedded filter according to claim 2, characterized in that: Also includes: A first protective layer; the first protective layer covers the first conductive layer.

4. The packaging structure of an embedded filter according to claim 3, characterized in that: The thickness of the first protection layer is the same as the height of the blind groove.

5. The packaging structure of an embedded filter according to claim 1, characterized in that: The glass-based substrate has at least three conductive layers and a protective layer.

6. The packaging structure of an embedded filter according to claim 3, characterized in that: The maximum normal stress of the abutment portion between the first protective layer and the blind groove is less than or equal to 77.906 MPa.

7. A packaging method for an embedded filter, characterized in that: The steps include: S1. providing a glass-based substrate, wherein a blind groove is provided on the glass-based substrate; S2, forming a routing morphology of a metal conductor of a first conductive layer in the blind groove; S3, covering the first conductive layer with a first protective layer, wherein the thickness of the first protective layer is the same as the height of the blind groove; S4. Etching the dielectric layer and the upper plate metal conductor on the basis of the first conductive layer, and sequentially forming the remaining conductive layer and the protective layer.

8. The packaging method of an embedded filter according to claim 7, characterized in that: The S1 specifically includes: S101, providing a glass-based substrate, and covering the blind groove mask area with a photolithography mask; S102, etching a pattern with a size not less than 0.5 mm*0.5 mm*5 um on the glass substrate by dry etching.

9. The packaging method of an embedded filter according to claim 7, characterized in that: The S2 specifically includes: S201, covering the first conductive layer mask area in the blind trench with a photolithography mask; S202, etching the non-first conductive layer mask area in the blind trench by using a photolithography process.

10. The method for packaging an embedded filter according to claim 7, characterized in that: The S4 specifically includes: S401, using PVD, PECVD and etching technology to complete the dielectric layer and the upper plate metal conductor on the basis of the first conductive layer; S402, forming the remaining conductive layer and the protective layer in sequence on the basis of the dielectric layer and the upper plate metal conductor, and interconnecting the conductive layers.

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