Filter module packaging structure

Abstract

The utility model discloses a filter module packaging structure. The filter module packaging structure comprises a substrate; the filter module is arranged on the substrate and comprises a plurality of filter chips and a plurality of non-filter chips; the isolating membrane is arranged on the upper surfaces of the substrate and the filter module, an open hole is preset in the isolating membrane, and the shape of the open hole is set based on whether the distances from the four edges of the non-filter chip to the corresponding filter chip or the edge position of the substrate in the vertical direction exceed a preset threshold value or not; the non-filter chips are completely or partially exposed in the open holes, the open holes are communicated with the bottoms of the corresponding non-filter chips, and a cavity is formed among the isolating membrane, the filter chips and the substrate; and the plastic package body wraps the substrate and the filter module. According to the utility model, the holes are formed in the isolating film in advance based on the relative positions of the filter module chips, and the bottom gaps of the non-filter chips can be filled with the subsequent plastic packaging material, so that the packaging reliability and yield of the filter module can be effectively improved.

Description

Technical Field

[0001] This utility model belongs to the field of filter module packaging technology, and specifically relates to a filter module packaging structure. Background Technology

[0002] Filter modules are a crucial component of the RF front-end, integrating various parts. Based on the functional requirements and physical characteristics of different components within the module, some parts require bottom encapsulation, such as surface acoustic wave (SAW) filter chips. Due to product performance and design requirements, the functional areas of the filter chip must not come into contact with any material; this is achieved through a cavity structure design. The bottom of the filter chip is not filled with plastic, thus forming a cavity to meet the filtering function requirements. In some packaging designs, certain non-filter components require bottom encapsulation, such as SOI (Silicon-On-Insulator) chips, to provide better protection and stability.

[0003] However, during the molding process, the film is adhered to the surface of the entire assembled substrate and the components to physically isolate the filter chip from the molding compound, ensuring a cavity is formed at the bottom of the filter chip to achieve the filtering function. But at the same time, because the film covers the entire substrate surface, other components or chips cannot be filled by the molding compound. This can lead to problems such as solder flow at the solder joints under special conditions, or internal gas expansion during subsequent high-temperature processes causing the product to burst or break, thus affecting the reliability of the entire filter module and ultimately causing product quality issues. Utility Model Content

[0004] To solve the above problems, this utility model designs and modifies the structure of the isolation membrane material. According to the position of the SOI chip, different shaped windows are designed on the isolation membrane to achieve the bottom filling of the non-filter chip with molding compound, and to ensure that the filter chip position is covered by the isolation membrane to isolate the molding compound and form a bottom cavity.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] A filter module packaging structure includes,

[0007] substrate;

[0008] A filter module disposed on the substrate, the filter module comprising a plurality of filter chips and a plurality of non-filter chips;

[0009] An isolation film is disposed on the upper surface of the substrate and the filter module, forming a cavity between the isolation film, the filter chip, and the substrate; an opening is pre-set on the isolation film corresponding to the non-filter chip, the non-filter chip being fully or partially exposed in the opening, and the opening being connected to the bottom of the corresponding non-filter chip; the shape of the opening is set based on whether the distance from each of the four sides of the non-filter chip to the edge of the corresponding filter chip or substrate in its vertical direction exceeds a preset threshold, and the opening shape includes rectangle, "U", "L", "I" and / or "I" shape;

[0010] And a molding compound that encapsulates the substrate and the filter module.

[0011] Furthermore, the preset threshold is 250µm.

[0012] Furthermore, when the distances from the four sides of the non-filter chip to the corresponding filter chip or substrate edge positions in its vertical direction all exceed a preset threshold, the opening shape is rectangular.

[0013] Furthermore, when the distance from three of the four sides of the non-filter chip to the corresponding edge of the filter chip or substrate in its vertical direction exceeds a preset threshold, the opening shape is "U".

[0014] Furthermore, when two adjacent sides of the non-filter chip have a distance from their respective vertical edges to the corresponding filter chip or substrate edge position that exceeds a preset threshold, the opening shape is "L" shaped.

[0015] When two of the four sides of the non-filter chip have a distance from their respective opposite sides to the edge of the filter chip or substrate in their vertical direction that exceeds a preset threshold, the opening shape is "I".

[0016] Furthermore, when only one of the four sides of the non-filter chip has a distance from the corresponding edge of the filter chip or substrate in its vertical direction that exceeds a preset threshold, the opening shape is "I" type.

[0017] Furthermore, the opening is formed by laser cutting or jig punching.

[0018] Furthermore, the substrate includes a packaged wafer or a PCB printed circuit board.

[0019] Furthermore, the materials used to form the encapsulated body include epoxy molding compounds and / or ceramic materials.

[0020] Furthermore, the separator is an electrically insulating film, and the material used to make the separator includes an aluminum nitride film and / or a scandium-doped aluminum nitride film.

[0021] The beneficial effects of this utility model are:

[0022] This invention utilizes a pre-formed perforated insulating film for coating before molding, and provides perforations of different shapes to meet the needs of products with different structural designs. In this solution, the bottom of the non-filter chip is connected to the perforation, so it will be filled with molding material during subsequent molding. This effectively improves the reliability and yield of filter module packaging structures and reduces costs. Attached Figure Description

[0023] Figure 1 A schematic diagram of a filter module packaging structure provided in an embodiment of this utility model;

[0024] Figure 2 A top view of a filter module packaging structure provided in an embodiment of this utility model;

[0025] Figure 3 for Figure 2 A cross-sectional view formed by cutting along line AA in the middle;

[0026] Figure 4 A schematic diagram showing the alignment of the isolation membrane and the substrate for mounting the filter module;

[0027] Figure 5 A schematic diagram showing that when there is window space around the SOI chip, the openings on the isolation film are rectangular in shape;

[0028] Figure 6 A schematic diagram showing the U-shaped openings on the separator when openings are reserved on three sides around the SOI chip.

[0029] Figure 7 A schematic diagram showing that when there are openings reserved on two adjacent sides around the SOI chip, the openings on the separator are L-shaped.

[0030] Figure 8 A schematic diagram showing the shape of the openings on the separator as "I" when there are openings reserved on two opposite sides around the SOI chip;

[0031] Figure 9 A schematic diagram showing the shape of the opening on the separator as "I" when only one side of the SOI chip is reserved for the opening space;

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Substrate; 2-Filter chip; 3-SOI chip; 4-Isolation film; 5-Opening; 6-Encapsulation. Detailed Implementation

[0034] To further understand this utility model, preferred embodiments of this utility model are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of this utility model, and not for limiting the scope of the claims of this utility model.

[0035] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show components related to this utility model and are not drawn according to the actual number, shape, and size of the components in the actual implementation. In the actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex. To keep the illustrations as concise as possible, not all structures are indicated in the drawings.

[0036] The present invention will now be further described in conjunction with specific embodiments.

[0037] Specifically, see Figures 1-3 This embodiment provides a filter module packaging structure, including,

[0038] substrate1;

[0039] A filter module flip-chip disposed on the substrate 1, the filter module comprising a plurality of filter chips 2 and a plurality of non-filter chips 3;

[0040] An isolation film 4 is disposed on the upper surface of the substrate 1 and the filter module. The isolation film 4 is an electrically insulating film. The material used to make the isolation film includes aluminum nitride film and / or scandium-doped aluminum nitride film. A cavity is formed between the isolation film 4, the filter chip 2, and the substrate 1.

[0041] The isolation membrane 4 has a pre-set opening 5. The shape of the opening 5 is set based on the relative position of the filter chip 2 and the non-filter chip 3, including but not limited to rectangular openings, "L" shaped openings, "U" shaped openings, "I" shaped openings and / or "I" shaped openings. The opening 5 is formed by laser cutting or jig punching method. The opening 5 is connected to the bottom of the corresponding non-filter chip 3.

[0042] And a molding compound 6, which encapsulates the substrate 1 and the filter module.

[0043] Specifically:

[0044] The substrate 1 includes a packaged wafer or a PCB (printed circuit board). The choice between a packaged wafer and a PCB depends on specific application requirements, cost considerations, and the designer's performance requirements. Packaged wafers offer higher integration and better electrical performance, while PCBs offer greater flexibility and easier manufacturing processes.

[0045] The filter module includes several filter chips 2 and several non-filter chips 3. This embodiment uses three filter chips 2 and one non-filter chip 3 (SOI chip) as an example. Due to different structural designs, the relative positions of the SOI chip 3 and the filter chip 2 are designed differently. The shape of the opening 5 on the isolation film 4 corresponding to the SOI chip varies. Specifically, when the distance from the edge of one side of the SOI chip to the nearest filter chip 2 or substrate 1 in the vertical direction exceeds a preset threshold, an opening 5 can be set on the isolation film 4 at the corresponding position. After the opening operation, the distance from the opening to the filter chip 2 is not less than the threshold, thus ensuring that a cavity is formed between the filter chip 2, substrate 1, and isolation film 4 after the opening 5 is set. The threshold is 250µm.

[0046] Different aperture shapes are set according to the relative positions of the SOI chip, filter chip 2, and substrate 3, specifically:

[0047] See Figure 4 and Figure 5 When the distance from the four edges of the SOI chip to the edge of the filter chip 2 or the substrate 1 in its vertical direction exceeds a preset threshold, the opening 5 on the isolation film 4 can cover the four edges of the SOI, so the shape of the opening 5 can be designed as a rectangle, and the SOI chip is completely exposed in the opening 5.

[0048] See Figure 6 When the distance from the three sides of the SOI chip to the edge of the filter chip 2 or the substrate 1 in its vertical direction exceeds a preset threshold, the opening shape can be set to "U" shape, that is, except for the three sides, the isolation film corresponding to the remaining side is not cut, and the three sides of the SOI chip are exposed in the opening.

[0049] See Figure 7 and Figure 8 When the distance from two edges of the SOI chip to the edge of the filter chip 2 or substrate 1 in its vertical direction exceeds a preset threshold, and when the two edges are adjacent, the opening 5 can be correspondingly set to an "L" shape, with the two adjacent edges exposed in the opening 5. When the two edges are opposite, the opening 5 can be correspondingly set to an "I" shape, with the two opposite edges exposed in the opening 5.

[0050] See Figure 9 When the distance from one edge of the SOI chip to the edge of the filter chip 2 or the substrate 1 in its vertical direction exceeds a preset threshold, an opening shape of "I" can be set at the corresponding edge position, and one edge of the SOI chip is exposed in the opening 5.

[0051] The materials used to make the molding compound 6 include epoxy resin molding compound and / or ceramic materials. The molding compound 6 acts as a protective cover to prevent the product from being subjected to physical damage and environmental factors. During the molding process, the molding compound material fills the gap between the bottom of the SOI chip and the substrate 1 through openings, providing additional mechanical support and thermal stress buffering, thereby improving the reliability and yield of the product.

[0052] Correspondingly, the method for fabricating the filter module packaging structure in this embodiment includes,

[0053] Prepare substrate 1, and mount filter chip 2 and SOI chip on substrate 1 according to the design scheme;

[0054] Based on the location and size of the SOI chip, determine the shape, location and size of the opening 5 of the separator 4, and make regional openings in the separator 4 by means of laser cutting or jig punching.

[0055] The substrate 1 with the pre-attached substrate and the opening-completed release liner 4 are aligned. After the position of the release liner 4 is adjusted, it is pressed in a vacuum environment by a laminating machine to obtain the laminated product.

[0056] The molding process involves encapsulating the chip with molding compound, which enters the bottom of the SOI chip through the gap in the window area, thus filling the bottom of the SOI chip with molding compound.

[0057] The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A filter module packaging structure, characterized in that, include, base(1); The filter module disposed on the substrate includes a plurality of filter chips (2) and a plurality of non-filter chips (3); An isolation film (4) is disposed on the upper surface of the substrate and the filter module, forming a cavity between the isolation film, the filter chip, and the substrate; an opening (5) is pre-set on the isolation film corresponding to the non-filter chip, the non-filter chip is fully or partially exposed in the opening, and the opening is connected to the bottom of the corresponding non-filter chip; the shape of the opening is set based on whether the distance from each of the four sides of the non-filter chip to the edge of the corresponding filter chip or substrate in its vertical direction exceeds a preset threshold, and the opening shape includes rectangle, "U" shape, "L" shape, "I" shape and / or "I" shape; And a molding compound (6) that encapsulates the substrate and the filter module.

2. The filter module packaging structure according to claim 1, characterized in that, The preset threshold is 250µm.

3. The filter module packaging structure according to claim 2, characterized in that, When the distance from the four sides of the non-filter chip to the corresponding filter chip or substrate edge in its vertical direction all exceed a preset threshold, the opening shape is rectangular.

4. The filter module packaging structure according to claim 2, characterized in that, When the distance from three of the four sides of the non-filter chip to the corresponding edge of the filter chip or substrate in its vertical direction exceeds a preset threshold, the opening shape is "U".

5. The filter module packaging structure according to claim 2, characterized in that, When two adjacent sides of the non-filter chip have a distance from their respective vertical edges to the edge of the filter chip or substrate that exceeds a preset threshold, the opening shape is "L". When two of the four sides of the non-filter chip have a distance from their respective opposite sides to the edge of the filter chip or substrate in their vertical direction that exceeds a preset threshold, the opening shape is "I".

6. The filter module packaging structure according to claim 2, characterized in that, When only one of the four sides of the non-filter chip has a distance from the edge of the corresponding filter chip or substrate in its vertical direction that exceeds a preset threshold, the opening shape is "I" type.

7. The filter module packaging structure according to any one of claims 1-6, characterized in that, The opening is formed by laser cutting or jig punching.

8. The filter module packaging structure according to claim 1, characterized in that, The substrate includes a packaged wafer or a PCB printed circuit board.

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